diff --git a/caps/BasePrincipal.cpp b/caps/BasePrincipal.cpp
index ade5b4e2e0..78b09bb249 100644
--- a/caps/BasePrincipal.cpp
+++ b/caps/BasePrincipal.cpp
@@ -624,13 +624,8 @@ BasePrincipal::GetOriginSuffix(nsACString& aOriginAttributes)
 NS_IMETHODIMP
 BasePrincipal::GetAppStatus(uint16_t* aAppStatus)
 {
-  if (AppId() == nsIScriptSecurityManager::UNKNOWN_APP_ID) {
-    NS_WARNING("Asking for app status on a principal with an unknown app id");
-    *aAppStatus = nsIPrincipal::APP_STATUS_NOT_INSTALLED;
-    return NS_OK;
-  }
-
-  *aAppStatus = nsScriptSecurityManager::AppStatusForPrincipal(this);
+  // TODO: Remove GetAppStatus.
+  *aAppStatus = nsIPrincipal::APP_STATUS_NOT_INSTALLED;
   return NS_OK;
 }
 
diff --git a/caps/nsPrincipal.cpp b/caps/nsPrincipal.cpp
index c9e66fef7a..169ee0cb8c 100644
--- a/caps/nsPrincipal.cpp
+++ b/caps/nsPrincipal.cpp
@@ -31,8 +31,6 @@
 #include "mozilla/Preferences.h"
 #include "mozilla/HashFunctions.h"
 
-#include "nsIAppsService.h"
-
 using namespace mozilla;
 
 static bool gCodeBasePrincipalSupport = false;
diff --git a/caps/nsScriptSecurityManager.cpp b/caps/nsScriptSecurityManager.cpp
index 9c70115482..9a17bda4b9 100644
--- a/caps/nsScriptSecurityManager.cpp
+++ b/caps/nsScriptSecurityManager.cpp
@@ -9,7 +9,6 @@
 
 #include "xpcpublic.h"
 #include "XPCWrapper.h"
-#include "nsIAppsService.h"
 #include "nsIInputStreamChannel.h"
 #include "nsILoadContext.h"
 #include "nsIServiceManager.h"
@@ -55,7 +54,6 @@
 #include "nsIChromeRegistry.h"
 #include "nsIContentSecurityPolicy.h"
 #include "nsIAsyncVerifyRedirectCallback.h"
-#include "mozIApplication.h"
 #include "mozilla/Preferences.h"
 #include "mozilla/dom/BindingUtils.h"
 #include "mozilla/dom/ContentParent.h"
@@ -240,12 +238,6 @@ nsScriptSecurityManager::SecurityHashURI(nsIURI* aURI)
     return NS_SecurityHashURI(aURI);
 }
 
-uint16_t
-nsScriptSecurityManager::AppStatusForPrincipal(nsIPrincipal *aPrin)
-{
-    return nsIPrincipal::APP_STATUS_NOT_INSTALLED;
-}
-
 /*
  * GetChannelResultPrincipal will return the principal that the resource
  * returned by this channel will use.  For example, if the resource is in
diff --git a/docshell/base/nsDocShell.cpp b/docshell/base/nsDocShell.cpp
index 39cee20f1f..770eb43119 100644
--- a/docshell/base/nsDocShell.cpp
+++ b/docshell/base/nsDocShell.cpp
@@ -193,7 +193,6 @@
 #include "nsSandboxFlags.h"
 #include "nsXULAppAPI.h"
 #include "nsDOMNavigationTiming.h"
-#include "nsIAppsService.h"
 #include "nsDSURIContentListener.h"
 #include "nsDocShellLoadTypes.h"
 #include "nsDocShellTransferableHooks.h"
diff --git a/dom/apps/AppsService.js b/dom/apps/AppsService.js
deleted file mode 100644
index e0a7ea041c..0000000000
--- a/dom/apps/AppsService.js
+++ /dev/null
@@ -1,114 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this file,
- * You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-"use strict"
-
-function debug(s) {
-  //dump("-*- AppsService.js: " + s + "\n");
-}
-
-const Cc = Components.classes;
-const Ci = Components.interfaces;
-const Cu = Components.utils;
-const Cr = Components.results;
-
-Cu.import("resource://gre/modules/XPCOMUtils.jsm");
-Cu.import("resource://gre/modules/Services.jsm");
-Cu.import("resource://gre/modules/Promise.jsm");
-
-const APPS_SERVICE_CID = Components.ID("{05072afa-92fe-45bf-ae22-39b69c117058}");
-
-function AppsService()
-{
-  debug("AppsService Constructor");
-  this.inParent = Cc["@mozilla.org/xre/app-info;1"].getService(Ci.nsIXULRuntime)
-                    .processType == Ci.nsIXULRuntime.PROCESS_TYPE_DEFAULT;
-  debug("inParent: " + this.inParent);
-  if (!this.inParent) {
-    Cu.import("resource://gre/modules/AppsServiceChild.jsm");
-  }
-}
-
-AppsService.prototype = {
-
-  isInvalidId: function(localId) {
-    return (localId == Ci.nsIScriptSecurityManager.NO_APP_ID ||
-            localId == Ci.nsIScriptSecurityManager.UNKNOWN_APP_ID);
-  },
-
-  getAppByManifestURL: function getAppByManifestURL(aManifestURL) {
-    debug("GetAppByManifestURL( " + aManifestURL + " )");
-    throw Cr.NS_ERROR_NOT_IMPLEMENTED;
-  },
-
-  getManifestFor: function getManifestFor(aManifestURL) {
-    debug("getManifestFor(" + aManifestURL + ")");
-    if (this.inParent) {
-      throw Cr.NS_ERROR_NOT_IMPLEMENTED;
-    } else {
-      return Promise.reject(
-        new Error("Calling getManifestFor() from child is not supported"));
-    }
-  },
-
-  getAppLocalIdByManifestURL: function getAppLocalIdByManifestURL(aManifestURL) {
-    debug("getAppLocalIdByManifestURL( " + aManifestURL + " )");
-    throw Cr.NS_ERROR_NOT_IMPLEMENTED;
-  },
-
-  getAppLocalIdByStoreId: function getAppLocalIdByStoreId(aStoreId) {
-    debug("getAppLocalIdByStoreId( " + aStoreId + " )");
-    throw Cr.NS_ERROR_NOT_IMPLEMENTED;
-  },
-
-  getAppByLocalId: function getAppByLocalId(aLocalId) {
-    debug("getAppByLocalId( " + aLocalId + " )");
-    if (this.isInvalidId(aLocalId)) {
-      return null;
-    }
-    throw Cr.NS_ERROR_NOT_IMPLEMENTED;
-  },
-
-  getManifestURLByLocalId: function getManifestURLByLocalId(aLocalId) {
-    debug("getManifestURLByLocalId( " + aLocalId + " )");
-    if (this.isInvalidId(aLocalId)) {
-      return null;
-    }
-    throw Cr.NS_ERROR_NOT_IMPLEMENTED;
-  },
-
-  getCoreAppsBasePath: function getCoreAppsBasePath() {
-    debug("getCoreAppsBasePath()");
-    throw Cr.NS_ERROR_NOT_IMPLEMENTED;
-  },
-
-  getWebAppsBasePath: function getWebAppsBasePath() {
-    debug("getWebAppsBasePath()");
-    throw Cr.NS_ERROR_NOT_IMPLEMENTED;
-  },
-
-  areAnyAppsInstalled: function() {
-    throw Cr.NS_ERROR_NOT_IMPLEMENTED;
-  },
-
-  getAppInfo: function getAppInfo(aAppId) {
-    debug("getAppInfo()");
-    throw Cr.NS_ERROR_NOT_IMPLEMENTED;
-  },
-
-  getScopeByLocalId: function(aLocalId) {
-    debug("getScopeByLocalId( " + aLocalId + " )");
-    if (this.isInvalidId(aLocalId)) {
-      return null;
-    }
-    // TODO : implement properly!
-    // We just return null for now to not break PushService.jsm
-    return null;
-  },
-
-  classID : APPS_SERVICE_CID,
-  QueryInterface : XPCOMUtils.generateQI([Ci.nsIAppsService])
-}
-
-this.NSGetFactory = XPCOMUtils.generateNSGetFactory([AppsService])
diff --git a/dom/apps/AppsService.manifest b/dom/apps/AppsService.manifest
deleted file mode 100644
index 2ed92d4e8a..0000000000
--- a/dom/apps/AppsService.manifest
+++ /dev/null
@@ -1,2 +0,0 @@
-component {05072afa-92fe-45bf-ae22-39b69c117058} AppsService.js
-contract @mozilla.org/AppsService;1 {05072afa-92fe-45bf-ae22-39b69c117058}
diff --git a/dom/apps/AppsServiceChild.jsm b/dom/apps/AppsServiceChild.jsm
deleted file mode 100644
index 4aca938af4..0000000000
--- a/dom/apps/AppsServiceChild.jsm
+++ /dev/null
@@ -1,408 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this file,
- * You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-"use strict";
-
-const Cu = Components.utils;
-const Cc = Components.classes;
-const Ci = Components.interfaces;
-
-// This module exposes a subset of the functionalities of the parent DOM
-// Registry to content processes, to be used from the AppsService component.
-
-this.EXPORTED_SYMBOLS = ["DOMApplicationRegistry", "WrappedManifestCache"];
-
-Cu.import("resource://gre/modules/AppsUtils.jsm");
-Cu.import("resource://gre/modules/Services.jsm");
-
-function debug(s) {
-  //dump("-*- AppsServiceChild.jsm: " + s + "\n");
-}
-
-const APPS_IPC_MSG_NAMES = [
-  "Webapps:AddApp",
-  "Webapps:RemoveApp",
-  "Webapps:UpdateApp",
-  "Webapps:CheckForUpdate:Return:KO",
-  "Webapps:FireEvent",
-  "Webapps:UpdateState"
-];
-
-// A simple cache for the wrapped manifests.
-this.WrappedManifestCache = {
-  _cache: { },
-
-  // Gets an entry from the cache, and populates the cache if needed.
-  get: function mcache_get(aManifestURL, aManifest, aWindow, aInnerWindowID) {
-    if (!aManifest) {
-      return;
-    }
-
-    if (!(aManifestURL in this._cache)) {
-      this._cache[aManifestURL] = { };
-    }
-
-    let winObjs = this._cache[aManifestURL];
-    if (!(aInnerWindowID in winObjs)) {
-      winObjs[aInnerWindowID] = Cu.cloneInto(aManifest, aWindow);
-    }
-
-    return winObjs[aInnerWindowID];
-  },
-
-  // Invalidates an entry in the cache.
-  evict: function mcache_evict(aManifestURL, aInnerWindowID) {
-    debug("Evicting manifest " + aManifestURL + " window ID " +
-          aInnerWindowID);
-    if (aManifestURL in this._cache) {
-      let winObjs = this._cache[aManifestURL];
-      if (aInnerWindowID in winObjs) {
-        delete winObjs[aInnerWindowID];
-      }
-
-      if (Object.keys(winObjs).length == 0) {
-        delete this._cache[aManifestURL];
-      }
-    }
-  },
-
-  observe: function(aSubject, aTopic, aData) {
-    // Clear the cache on memory pressure.
-    this._cache = { };
-    Cu.forceGC();
-  },
-
-  init: function() {
-    Services.obs.addObserver(this, "memory-pressure", false);
-  }
-};
-
-this.WrappedManifestCache.init();
-
-
-// DOMApplicationRegistry keeps a cache containing a list of apps in the device.
-// This information is updated with the data received from the main process and
-// it is queried by the DOM objects to set their state.
-// This module handle all the messages broadcasted from the parent process,
-// including DOM events, which are dispatched to the corresponding DOM objects.
-
-this.DOMApplicationRegistry = {
-  // DOMApps will hold a list of arrays of weak references to
-  // mozIDOMApplication objects indexed by manifest URL.
-  DOMApps: {},
-
-  ready: false,
-  webapps: null,
-
-  init: function init() {
-    this.cpmm = Cc["@mozilla.org/childprocessmessagemanager;1"]
-                  .getService(Ci.nsISyncMessageSender);
-
-    APPS_IPC_MSG_NAMES.forEach((function(aMsgName) {
-      this.cpmm.addMessageListener(aMsgName, this);
-    }).bind(this));
-
-    this.webapps = { };
-    // We need a fast mapping from localId -> app, so we add an index.
-    // We also add the manifest to the app object.
-    this.localIdIndex = { };
-    for (let id in this.webapps) {
-      let app = this.webapps[id];
-      this.localIdIndex[app.localId] = app;
-      app.manifest = list.manifests[id];
-    }
-
-    Services.obs.addObserver(this, "xpcom-shutdown", false);
-  },
-
-  observe: function(aSubject, aTopic, aData) {
-    // cpmm.addMessageListener causes the DOMApplicationRegistry object to
-    // live forever if we don't clean up properly.
-    this.webapps = null;
-    this.DOMApps = null;
-
-    APPS_IPC_MSG_NAMES.forEach((aMsgName) => {
-      this.cpmm.removeMessageListener(aMsgName, this);
-    });
-  },
-
-  receiveMessage: function receiveMessage(aMessage) {
-    debug("Received " + aMessage.name + " message.");
-    let msg = aMessage.data;
-    switch (aMessage.name) {
-      case "Webapps:AddApp":
-        this.webapps[msg.id] = msg.app;
-        this.localIdIndex[msg.app.localId] = msg.app;
-        if (msg.manifest) {
-          this.webapps[msg.id].manifest = msg.manifest;
-        }
-        break;
-      case "Webapps:RemoveApp":
-        delete this.DOMApps[this.webapps[msg.id].manifestURL];
-        delete this.localIdIndex[this.webapps[msg.id].localId];
-        delete this.webapps[msg.id];
-        break;
-      case "Webapps:UpdateApp":
-        let app = this.webapps[msg.oldId];
-        if (!app) {
-          return;
-        }
-
-        if (msg.app) {
-          for (let prop in msg.app) {
-            app[prop] = msg.app[prop];
-          }
-        }
-
-        this.webapps[msg.newId] = app;
-        this.localIdIndex[app.localId] = app;
-        delete this.webapps[msg.oldId];
-
-        let apps = this.DOMApps[msg.app.manifestURL];
-        if (!apps) {
-          return;
-        }
-        for (let i = 0; i < apps.length; i++) {
-          let domApp = apps[i].get();
-          if (!domApp || domApp._window === null) {
-            apps.splice(i, 1);
-            continue;
-          }
-          domApp._proxy = new Proxy(domApp, {
-            get: function(target, prop) {
-              if (!DOMApplicationRegistry.webapps[msg.newId]) {
-                return;
-              }
-              return DOMApplicationRegistry.webapps[msg.newId][prop];
-            },
-            set: function(target, prop, val) {
-              if (!DOMApplicationRegistry.webapps[msg.newId]) {
-                return;
-              }
-              DOMApplicationRegistry.webapps[msg.newId][prop] = val;
-              return;
-            },
-          });
-        }
-        break;
-      case "Webapps:FireEvent":
-        this._fireEvent(aMessage);
-        break;
-      case "Webapps:UpdateState":
-        this._updateState(msg);
-        break;
-      case "Webapps:CheckForUpdate:Return:KO":
-        let DOMApps = this.DOMApps[msg.manifestURL];
-        if (!DOMApps || !msg.requestID) {
-          return;
-        }
-        DOMApps.forEach((DOMApp) => {
-          let domApp = DOMApp.get();
-          if (domApp && msg.requestID) {
-            domApp._fireRequestResult(aMessage, true /* aIsError */);
-          }
-        });
-        break;
-    }
-  },
-
-  /**
-   * mozIDOMApplication management
-   */
-
-  // Every time a DOM app is created, we save a weak reference to it that will
-  // be used to dispatch events and fire request results.
-  addDOMApp: function(aApp, aManifestURL, aId) {
-    let weakRef = Cu.getWeakReference(aApp);
-
-    if (!this.DOMApps[aManifestURL]) {
-      this.DOMApps[aManifestURL] = [];
-    }
-
-    let apps = this.DOMApps[aManifestURL];
-
-    // Get rid of dead weak references.
-    for (let i = 0; i < apps.length; i++) {
-      let app = apps[i].get();
-      if (!app || app._window === null) {
-        apps.splice(i, 1);
-      }
-    }
-
-    apps.push(weakRef);
-
-    // Each DOM app contains a proxy object used to build their state. We
-    // return the handler for this proxy object with traps to get and set
-    // app properties kept in the DOMApplicationRegistry app cache.
-    return {
-      get: function(target, prop) {
-        if (!DOMApplicationRegistry.webapps[aId]) {
-          return;
-        }
-
-        if (prop in DOMApplicationRegistry.webapps[aId]) {
-          return DOMApplicationRegistry.webapps[aId][prop];
-        }
-        return null;
-      },
-      set: function(target, prop, val) {
-        if (!DOMApplicationRegistry.webapps[aId]) {
-          return;
-        }
-        DOMApplicationRegistry.webapps[aId][prop] = val;
-        return;
-      },
-    };
-  },
-
-  _fireEvent: function(aMessage) {
-    let msg = aMessage.data;
-    debug("_fireEvent " + JSON.stringify(msg));
-    if (!this.DOMApps || !msg.manifestURL || !msg.eventType) {
-      return;
-    }
-
-    let DOMApps = this.DOMApps[msg.manifestURL];
-    if (!DOMApps) {
-      return;
-    }
-
-    // The parent might ask childs to trigger more than one event in one
-    // shot, so in order to avoid needless IPC we allow an array for the
-    // 'eventType' IPC message field.
-    if (!Array.isArray(msg.eventType)) {
-      msg.eventType = [msg.eventType];
-    }
-
-    DOMApps.forEach((DOMApp) => {
-      let domApp = DOMApp.get();
-      if (!domApp) {
-        return;
-      }
-      msg.eventType.forEach((aEventType) => {
-        if ('on' + aEventType in domApp) {
-          domApp._fireEvent(aEventType);
-        }
-      });
-
-      if (msg.requestID) {
-        aMessage.data.result = msg.manifestURL;
-        domApp._fireRequestResult(aMessage);
-      }
-    });
-  },
-
-  _updateState: function(aMessage) {
-    if (!this.DOMApps || !aMessage.id) {
-      return;
-    }
-
-    let app = this.webapps[aMessage.id];
-    if (!app) {
-      return;
-    }
-
-    if (aMessage.app) {
-      for (let prop in aMessage.app) {
-        app[prop] = aMessage.app[prop];
-      }
-    }
-
-    if ("error" in aMessage) {
-      app.downloadError = aMessage.error;
-    }
-
-    if (aMessage.manifest) {
-      app.manifest = aMessage.manifest;
-      // Evict the wrapped manifest cache for all the affected DOM objects.
-      let DOMApps = this.DOMApps[app.manifestURL];
-      if (!DOMApps) {
-        return;
-      }
-      DOMApps.forEach((DOMApp) => {
-        let domApp = DOMApp.get();
-        if (!domApp) {
-          return;
-        }
-        WrappedManifestCache.evict(app.manifestURL, domApp.innerWindowID);
-      });
-    }
-  },
-
-  getAll: function(aCallback) {
-    debug("getAll()\n");
-    if (!aCallback || typeof aCallback !== "function") {
-      return;
-    }
-
-    let res = [];
-    for (let id in this.webapps) {
-      res.push(this.webapps[id]);
-    }
-    aCallback(res);
-  },
-
-  getAdditionalLanguages: function(aManifestURL) {
-    for (let id in this.webapps) {
-      if (this.webapps[id].manifestURL == aManifestURL) {
-        return this.webapps[id].additionalLanguages || {};
-      }
-    }
-    return {};
-  },
-
-  /**
-   * nsIAppsService API
-   */
-  getAppByManifestURL: function getAppByManifestURL(aManifestURL) {
-    debug("getAppByManifestURL " + aManifestURL);
-    return AppsUtils.getAppByManifestURL(this.webapps, aManifestURL);
-  },
-
-  getAppLocalIdByManifestURL: function getAppLocalIdByManifestURL(aManifestURL) {
-    debug("getAppLocalIdByManifestURL " + aManifestURL);
-    return AppsUtils.getAppLocalIdByManifestURL(this.webapps, aManifestURL);
-  },
-
-  getAppLocalIdByStoreId: function(aStoreId) {
-    debug("getAppLocalIdByStoreId:" + aStoreId);
-    return AppsUtils.getAppLocalIdByStoreId(this.webapps, aStoreId);
-  },
-
-  getAppByLocalId: function getAppByLocalId(aLocalId) {
-    debug("getAppByLocalId " + aLocalId + " - ready: " + this.ready);
-    let app = this.localIdIndex[aLocalId];
-    if (!app) {
-      debug("Ouch, No app!");
-      return null;
-    }
-
-    return new mozIApplication(app);
-  },
-
-  getManifestURLByLocalId: function getManifestURLByLocalId(aLocalId) {
-    debug("getManifestURLByLocalId " + aLocalId);
-    return AppsUtils.getManifestURLByLocalId(this.webapps, aLocalId);
-  },
-
-  getCoreAppsBasePath: function getCoreAppsBasePath() {
-    debug("getCoreAppsBasePath() not yet supported on child!");
-    return null;
-  },
-
-  getWebAppsBasePath: function getWebAppsBasePath() {
-    debug("getWebAppsBasePath() not yet supported on child!");
-    return null;
-  },
-
-  areAnyAppsInstalled: function() {
-    return AppsUtils.areAnyAppsInstalled(this.webapps);
-  },
-
-  getAppInfo: function getAppInfo(aAppId) {
-    return AppsUtils.getAppInfo(this.webapps, aAppId);
-  }
-}
-
-DOMApplicationRegistry.init();
diff --git a/dom/apps/AppsUtils.jsm b/dom/apps/AppsUtils.jsm
index d24dee8c23..5a70b352f1 100644
--- a/dom/apps/AppsUtils.jsm
+++ b/dom/apps/AppsUtils.jsm
@@ -19,14 +19,10 @@ XPCOMUtils.defineLazyModuleGetter(this, "FileUtils",
 XPCOMUtils.defineLazyModuleGetter(this, "NetUtil",
   "resource://gre/modules/NetUtil.jsm");
 
-XPCOMUtils.defineLazyServiceGetter(this, "appsService",
-                                   "@mozilla.org/AppsService;1",
-                                   "nsIAppsService");
-
-// Shared code for AppsServiceChild.jsm, Webapps.jsm and Webapps.js
+// Shared code for Webapps.jsm and Webapps.js
 
 this.EXPORTED_SYMBOLS =
-  ["AppsUtils", "ManifestHelper", "isAbsoluteURI", "mozIApplication"];
+  ["AppsUtils", "ManifestHelper", "isAbsoluteURI"];
 
 function debug(s) {
   //dump("-*- AppsUtils.jsm: " + s + "\n");
@@ -39,46 +35,6 @@ this.isAbsoluteURI = function(aURI) {
          Services.io.newURI(aURI, null, bar).prePath != bar.prePath;
 }
 
-this.mozIApplication = function(aApp) {
-  _setAppProperties(this, aApp);
-}
-
-mozIApplication.prototype = {
-  hasPermission: function(aPermission) {
-    // This helper checks an URI inside |aApp|'s origin and part of |aApp| has a
-    // specific permission. It is not checking if browsers inside |aApp| have such
-    // permission.
-    let perm = Services.perms.testExactPermissionFromPrincipal(this.principal,
-                                                               aPermission);
-    return (perm === Ci.nsIPermissionManager.ALLOW_ACTION);
-  },
-
-  get principal() {
-    if (this._principal) {
-      return this._principal;
-    }
-
-    this._principal = null;
-
-    try {
-      this._principal = Services.scriptSecurityManager.createCodebasePrincipal(
-        Services.io.newURI(this.origin, null, null),
-        {appId: this.localId});
-    } catch(e) {
-      dump("Could not create app principal " + e + "\n");
-    }
-
-    return this._principal;
-  },
-
-  QueryInterface: function(aIID) {
-    if (aIID.equals(Ci.mozIApplication) ||
-        aIID.equals(Ci.nsISupports))
-      return this;
-    throw Cr.NS_ERROR_NO_INTERFACE;
-  }
-}
-
 function _setAppProperties(aObj, aApp) {
   aObj.name = aApp.name;
   aObj.csp = aApp.csp;
@@ -217,21 +173,6 @@ this.AppsUtils = {
     return aPagePath.substr(pathPos, pathLen);
   },
 
-  getAppByManifestURL: function getAppByManifestURL(aApps, aManifestURL) {
-    debug("getAppByManifestURL " + aManifestURL);
-    // This could be O(1) if |webapps| was a dictionary indexed on manifestURL
-    // which should be the unique app identifier.
-    // It's currently O(n).
-    for (let id in aApps) {
-      let app = aApps[id];
-      if (app.manifestURL == aManifestURL) {
-        return new mozIApplication(app);
-      }
-    }
-
-    return null;
-  },
-
   getManifestFor: function getManifestFor(aManifestURL) {
     debug("getManifestFor(" + aManifestURL + ")");
     return DOMApplicationRegistry.getManifestFor(aManifestURL);
@@ -259,18 +200,6 @@ this.AppsUtils = {
     return Ci.nsIScriptSecurityManager.NO_APP_ID;
   },
 
-  getAppByLocalId: function getAppByLocalId(aApps, aLocalId) {
-    debug("getAppByLocalId " + aLocalId);
-    for (let id in aApps) {
-      let app = aApps[id];
-      if (app.localId == aLocalId) {
-        return new mozIApplication(app);
-      }
-    }
-
-    return null;
-  },
-
   getManifestURLByLocalId: function getManifestURLByLocalId(aApps, aLocalId) {
     debug("getManifestURLByLocalId " + aLocalId);
     for (let id in aApps) {
@@ -697,14 +626,6 @@ this.AppsUtils = {
     return this.computeHash(JSON.stringify(aObject));
   },
 
-  getAppManifestURLFromWindow: function(aWindow) {
-    let appId = aWindow.document.nodePrincipal.appId;
-    if (appId === Ci.nsIScriptSecurityManager.NO_APP_ID) {
-      return null;
-    }
-
-    return appsService.getManifestURLByLocalId(appId);
-  },
 }
 
 /**
diff --git a/dom/apps/moz.build b/dom/apps/moz.build
index 27ac62947e..d16c926bc7 100644
--- a/dom/apps/moz.build
+++ b/dom/apps/moz.build
@@ -5,13 +5,7 @@
 
 XPCSHELL_TESTS_MANIFESTS += ['tests/unit/xpcshell.ini']
 
-EXTRA_COMPONENTS += [
-    'AppsService.js',
-    'AppsService.manifest',
-]
-
 EXTRA_JS_MODULES += [
-    'AppsServiceChild.jsm',
     'AppsUtils.jsm',
     'PermissionsInstaller.jsm',
     'PermissionsTable.jsm',
diff --git a/dom/apps/tests/unit/test_moziapplication.js b/dom/apps/tests/unit/test_moziapplication.js
deleted file mode 100644
index dbcf2372a3..0000000000
--- a/dom/apps/tests/unit/test_moziapplication.js
+++ /dev/null
@@ -1,64 +0,0 @@
-/* Any copyright is dedicated to the Public Domain.
-   http://creativecommons.org/publicdomain/zero/1.0/ */
-
-var {classes: Cc, interfaces: Ci, utils: Cu} = Components;
-
-Cu.import("resource:///modules/AppsUtils.jsm");
-
-add_test(() => {
-  let app = {
-    name: "TestApp",
-    csp: "aCsp",
-    installOrigin: "http://installorigin.com",
-    origin: "http://www.example.com",
-    installTime: Date.now(),
-    manifestURL: "http://www.example.com/manifest.webapp",
-    appStatus: Ci.nsIPrincipal.APP_STATUS_NOT_INSTALLED,
-    removable: false,
-    id: 123,
-    localId: 123,
-    basePath: "/",
-    progress: 1.0,
-    installState: "installed",
-    downloadAvailable: false,
-    downloading: false,
-    lastUpdateCheck: Date.now(),
-    updateTime: Date.now(),
-    etag: "aEtag",
-    packageEtag: "aPackageEtag",
-    manifestHash: "aManifestHash",
-    packageHash: "aPackageHash",
-    staged: false,
-    installerAppId: 345,
-    installerIsBrowser: false,
-    storeId: "aStoreId",
-    storeVersion: 1,
-    role: "aRole",
-    kind: "aKind",
-    enabled: true,
-    sideloaded: false
-  };
-
-  let mozapp = new mozIApplication(app);
-
-  Object.keys(app).forEach((key) => {
-    if (key == "principal") {
-      return;
-    }
-    Assert.equal(app[key], mozapp[key],
-                 "app[" + key + "] should be equal to mozapp[" + key + "]");
-  });
-
-  Assert.ok(mozapp.principal, "app principal should exist");
-  let expectedPrincipalOrigin = app.origin + "^appId=" + app.localId;
-  Assert.equal(mozapp.principal.origin, expectedPrincipalOrigin,
-               "app principal origin ok");
-  Assert.equal(mozapp.principal.appId, app.localId, "app principal appId ok");
-  Assert.equal(mozapp.principal.isInIsolatedMozBrowserElement, false,
-               "app principal isInIsolatedMozBrowserElement ok");
-  run_next_test();
-});
-
-function run_test() {
-  run_next_test();
-}
diff --git a/dom/apps/tests/unit/xpcshell.ini b/dom/apps/tests/unit/xpcshell.ini
index 9745b198f2..c7df08d02d 100644
--- a/dom/apps/tests/unit/xpcshell.ini
+++ b/dom/apps/tests/unit/xpcshell.ini
@@ -2,4 +2,3 @@
 
 [test_manifestSanitizer.js]
 [test_manifestHelper.js]
-[test_moziapplication.js]
diff --git a/dom/base/Navigator.cpp b/dom/base/Navigator.cpp
index 9ff4519d82..26789c2881 100644
--- a/dom/base/Navigator.cpp
+++ b/dom/base/Navigator.cpp
@@ -62,7 +62,6 @@
 #include "nsIHttpChannelInternal.h"
 #include "TimeManager.h"
 #include "nsStreamUtils.h"
-#include "nsIAppsService.h"
 #include "WidgetUtils.h"
 #include "mozilla/dom/MediaDevices.h"
 #include "MediaManager.h"
diff --git a/dom/base/nsFrameLoader.cpp b/dom/base/nsFrameLoader.cpp
index 9c10b9af08..8db5e6fe9d 100644
--- a/dom/base/nsFrameLoader.cpp
+++ b/dom/base/nsFrameLoader.cpp
@@ -13,7 +13,6 @@
 #include "prenv.h"
 
 #include "nsDocShell.h"
-#include "nsIAppsService.h"
 #include "nsIDOMHTMLIFrameElement.h"
 #include "nsIDOMHTMLFrameElement.h"
 #include "nsIDOMMozBrowserFrame.h"
diff --git a/dom/html/nsBrowserElement.cpp b/dom/html/nsBrowserElement.cpp
index 1292d7673f..fb991caba9 100644
--- a/dom/html/nsBrowserElement.cpp
+++ b/dom/html/nsBrowserElement.cpp
@@ -18,7 +18,6 @@
 #include "nsComponentManagerUtils.h"
 #include "nsContentUtils.h"
 #include "nsFrameLoader.h"
-#include "nsIAppsService.h"
 #include "nsIDOMDocument.h"
 #include "nsIDOMDOMRequest.h"
 #include "nsIDOMElement.h"
diff --git a/dom/indexedDB/ActorsParent.cpp b/dom/indexedDB/ActorsParent.cpp
index 7cccb6462e..3ea646d25a 100644
--- a/dom/indexedDB/ActorsParent.cpp
+++ b/dom/indexedDB/ActorsParent.cpp
@@ -74,7 +74,6 @@
 #include "nsHashKeys.h"
 #include "nsNetUtil.h"
 #include "nsISimpleEnumerator.h"
-#include "nsIAppsService.h"
 #include "nsIEventTarget.h"
 #include "nsIFile.h"
 #include "nsIFileURL.h"
diff --git a/dom/inputmethod/Keyboard.jsm b/dom/inputmethod/Keyboard.jsm
index e110df6fdd..13a41a5025 100644
--- a/dom/inputmethod/Keyboard.jsm
+++ b/dom/inputmethod/Keyboard.jsm
@@ -19,10 +19,6 @@ XPCOMUtils.defineLazyServiceGetter(this, "ppmm",
 XPCOMUtils.defineLazyModuleGetter(this, "SystemAppProxy",
                                   "resource://gre/modules/SystemAppProxy.jsm");
 
-XPCOMUtils.defineLazyGetter(this, "appsService", function() {
-  return Cc["@mozilla.org/AppsService;1"].getService(Ci.nsIAppsService);
-});
-
 XPCOMUtils.defineLazyGetter(this, "hardwareKeyHandler", function() {
   return null;
 });
@@ -554,24 +550,6 @@ InputRegistryGlue.prototype.addInput = function(msg, mm) {
     mm: mm,
     requestId: msg.data.requestId
   });
-
-  let manifestURL = appsService.getManifestURLByLocalId(msg.data.appId);
-
-  Keyboard.sendToSystem('System:InputRegistry:Add', {
-    id: msgId,
-    manifestURL: manifestURL,
-    inputId: msg.data.inputId,
-    inputManifest: msg.data.inputManifest
-  });
-
-  // XXX: To be removed when content migrate away from mozChromeEvents.
-  SystemAppProxy.dispatchEvent({
-    type: 'inputregistry-add',
-    id: msgId,
-    manifestURL: manifestURL,
-    inputId: msg.data.inputId,
-    inputManifest: msg.data.inputManifest
-  });
 };
 
 InputRegistryGlue.prototype.removeInput = function(msg, mm) {
@@ -580,22 +558,6 @@ InputRegistryGlue.prototype.removeInput = function(msg, mm) {
     mm: mm,
     requestId: msg.data.requestId
   });
-
-  let manifestURL = appsService.getManifestURLByLocalId(msg.data.appId);
-
-  Keyboard.sendToSystem('System:InputRegistry:Remove', {
-    id: msgId,
-    manifestURL: manifestURL,
-    inputId: msg.data.inputId
-  });
-
-  // XXX: To be removed when content migrate away from mozChromeEvents.
-  SystemAppProxy.dispatchEvent({
-    type: 'inputregistry-remove',
-    id: msgId,
-    manifestURL: manifestURL,
-    inputId: msg.data.inputId
-  });
 };
 
 InputRegistryGlue.prototype.returnMessage = function(detail) {
diff --git a/dom/interfaces/apps/moz.build b/dom/interfaces/apps/moz.build
deleted file mode 100644
index 018bda3d80..0000000000
--- a/dom/interfaces/apps/moz.build
+++ /dev/null
@@ -1,13 +0,0 @@
-# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-XPIDL_SOURCES += [
-    'mozIApplication.idl',
-    'mozIApplicationClearPrivateDataParams.idl',
-    'nsIAppsService.idl',
-]
-
-XPIDL_MODULE = 'dom_apps'
-
diff --git a/dom/interfaces/apps/mozIApplication.idl b/dom/interfaces/apps/mozIApplication.idl
deleted file mode 100644
index 3ec506cdba..0000000000
--- a/dom/interfaces/apps/mozIApplication.idl
+++ /dev/null
@@ -1,58 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this file,
- * You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#include "domstubs.idl"
-
-interface nsIPrincipal;
-
-/**
- * We expose Gecko-internal helpers related to "web apps" through this
- * sub-interface.
- */
-[scriptable, uuid(e76aa5e0-80b2-404f-bccc-1067828bb6ed)]
-interface mozIApplication: nsISupports
-{
-  /* Return true if this app has |permission|. */
-  boolean hasPermission(in string permission);
-
-  /* Application status as defined in nsIPrincipal. */
-  readonly attribute unsigned short appStatus;
-
-  /* Returns the uuid of the app. */
-  readonly attribute DOMString id;
-
-  /* Returns the origin of the app. */
-  readonly attribute DOMString origin;
-
-  /* Returns the manifest url of the app. */
-  readonly attribute DOMString manifestURL;
-
-  /* Returns the local id of the app. */
-  readonly attribute unsigned long localId;
-
-  /* Returns the base directory for the app */
-  readonly attribute DOMString basePath;
-
-  /* Name copied from the manifest */
-  readonly attribute DOMString name;
-
-  /* CSP copied from the manifest */
-  readonly attribute DOMString csp;
-
-  /* Store ID if the app is installed from a store */
-  readonly attribute DOMString storeID;
-
-  /* Store version if the app is installed from a store */
-  readonly attribute unsigned long storeVersion;
-
-  /* role copied from the manifest */
-  readonly attribute DOMString role;
-
-  /* Returns the kind of the app. */
-  readonly attribute DOMString kind;
-
-  /* Returns the app's principal */
-  readonly attribute nsIPrincipal principal;
-};
diff --git a/dom/interfaces/apps/mozIApplicationClearPrivateDataParams.idl b/dom/interfaces/apps/mozIApplicationClearPrivateDataParams.idl
deleted file mode 100644
index 924fc3f2d3..0000000000
--- a/dom/interfaces/apps/mozIApplicationClearPrivateDataParams.idl
+++ /dev/null
@@ -1,18 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this file,
- * You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#include "nsISupports.idl"
-
-[scriptable, uuid(ba0e6c8e-8c03-4b9b-8f9b-4fb14216f56e)]
-interface mozIApplicationClearPrivateDataParams : nsISupports
-{
-  readonly attribute unsigned long appId;
-  readonly attribute boolean browserOnly;
-};
-
-%{C++
-#define TOPIC_WEB_APP_CLEAR_DATA "webapps-clear-data"
-#define TOPIC_CLEAR_ORIGIN_DATA "clear-origin-attributes-data"
-%}
diff --git a/dom/interfaces/apps/nsIAppsService.idl b/dom/interfaces/apps/nsIAppsService.idl
deleted file mode 100644
index 4e91a50eca..0000000000
--- a/dom/interfaces/apps/nsIAppsService.idl
+++ /dev/null
@@ -1,75 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this file,
- * You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#include "domstubs.idl"
-
-interface mozIApplication;
-interface nsIURI;
-
-%{C++
-#define APPS_SERVICE_CID { 0x05072afa, 0x92fe, 0x45bf, { 0xae, 0x22, 0x39, 0xb6, 0x9c, 0x11, 0x70, 0x58 } }
-#define APPS_SERVICE_CONTRACTID "@mozilla.org/AppsService;1"
-%}
-
-/*
- * This service allows accessing some DOMApplicationRegistry methods from
- * non-javascript code.
- */
-[scriptable, uuid(711cfab6-7b72-4aa2-a60c-17952ea05661)]
-interface nsIAppsService : nsISupports
-{
-  mozIApplication getAppByManifestURL(in DOMString manifestURL);
-
-  /**
-   * Returns a Promise for the manifest for a given manifestURL.
-   * This is only supported in the parent process: the promise will be rejected
-   * in content processes.
-   */
-  jsval getManifestFor(in DOMString manifestURL);
-
-  /**
-   * Returns the |localId| of the app associated with the |manifestURL| passed
-   * in parameter.
-   * Returns nsIScriptSecurityManager::NO_APP_ID if |manifestURL| isn't a valid
-   * installed manifest URL.
-   */
-  unsigned long getAppLocalIdByManifestURL(in DOMString manifestURL);
-
-  /**
-   * Returns the application associated to this localId.
-   */
-  mozIApplication getAppByLocalId(in unsigned long localId);
-
-  /**
-   * Returns the manifest URL associated to this localId.
-   */
-  DOMString getManifestURLByLocalId(in unsigned long localId);
-
-  /**
-   * Returns the basepath for core apps
-   */
-  DOMString getCoreAppsBasePath();
-
-  /**
-   * Returns the basepath for regular packaged apps
-   */
-  DOMString getWebAppsBasePath();
-
-  /**
-   * Returns true if at least one app is in the registry.
-   */
-  boolean areAnyAppsInstalled();
-
-  jsval getAppInfo(in DOMString appId);
-
-  /**
-   * Returns the localId if the app was installed from a store
-   */
-  DOMString getAppLocalIdByStoreId(in DOMString storeID);
-
-  /**
-   * Returns the scope for app to use with service workers.
-   */
-  DOMString getScopeByLocalId(in unsigned long localId);
-};
diff --git a/dom/ipc/ContentParent.cpp b/dom/ipc/ContentParent.cpp
index 319b20d1f9..b1ee02095c 100644
--- a/dom/ipc/ContentParent.cpp
+++ b/dom/ipc/ContentParent.cpp
@@ -96,7 +96,6 @@
 #include "nsFrameMessageManager.h"
 #include "nsHashPropertyBag.h"
 #include "nsIAlertsService.h"
-#include "nsIAppsService.h"
 #include "nsIClipboard.h"
 #include "nsContentPermissionHelper.h"
 #include "nsICycleCollectorListener.h"
diff --git a/dom/ipc/TabChild.cpp b/dom/ipc/TabChild.cpp
index b274345786..ed183eb1b2 100644
--- a/dom/ipc/TabChild.cpp
+++ b/dom/ipc/TabChild.cpp
@@ -44,7 +44,6 @@
 #include "mozilla/TextEvents.h"
 #include "mozilla/TouchEvents.h"
 #include "mozilla/Unused.h"
-#include "mozIApplication.h"
 #include "nsContentUtils.h"
 #include "nsCSSFrameConstructor.h"
 #include "nsDocShell.h"
@@ -98,7 +97,6 @@
 #include "nsColorPickerProxy.h"
 #include "nsContentPermissionHelper.h"
 #include "nsPresShell.h"
-#include "nsIAppsService.h"
 #include "nsNetUtil.h"
 #include "nsIPermissionManager.h"
 #include "nsIURILoader.h"
diff --git a/dom/moz.build b/dom/moz.build
index 446fc25126..585dcce59c 100644
--- a/dom/moz.build
+++ b/dom/moz.build
@@ -29,7 +29,6 @@ interfaces = [
     'permission',
     'svg',
     'smil',
-    'apps',
     'push',
 ]
 
diff --git a/dom/workers/ServiceWorkerManager.h b/dom/workers/ServiceWorkerManager.h
index bbf185ff81..8d2600ea48 100644
--- a/dom/workers/ServiceWorkerManager.h
+++ b/dom/workers/ServiceWorkerManager.h
@@ -32,7 +32,6 @@
 #include "nsTArrayForwardDeclare.h"
 #include "nsTObserverArray.h"
 
-class mozIApplicationClearPrivateDataParams;
 class nsIConsoleReportCollector;
 
 namespace mozilla {
diff --git a/extensions/cookie/nsPermissionManager.cpp b/extensions/cookie/nsPermissionManager.cpp
index 426cd79486..f8fa542e76 100644
--- a/extensions/cookie/nsPermissionManager.cpp
+++ b/extensions/cookie/nsPermissionManager.cpp
@@ -29,7 +29,6 @@
 #include "nsIPrincipal.h"
 #include "nsContentUtils.h"
 #include "nsIScriptSecurityManager.h"
-#include "nsIAppsService.h"
 #include "nsIEffectiveTLDService.h"
 #include "nsPIDOMWindow.h"
 #include "nsIDocument.h"
diff --git a/ipc/glue/BackgroundParentImpl.cpp b/ipc/glue/BackgroundParentImpl.cpp
index 1d11ae8f6c..931bc5bc9c 100644
--- a/ipc/glue/BackgroundParentImpl.cpp
+++ b/ipc/glue/BackgroundParentImpl.cpp
@@ -40,7 +40,6 @@
 #include "mozilla/layout/VsyncParent.h"
 #include "mozilla/dom/network/UDPSocketParent.h"
 #include "mozilla/Preferences.h"
-#include "nsIAppsService.h"
 #include "nsNetUtil.h"
 #include "nsIScriptSecurityManager.h"
 #include "nsProxyRelease.h"
diff --git a/layout/build/nsLayoutModule.cpp b/layout/build/nsLayoutModule.cpp
index 2d4866b00b..36135cd605 100644
--- a/layout/build/nsLayoutModule.cpp
+++ b/layout/build/nsLayoutModule.cpp
@@ -79,7 +79,6 @@
 #include "DOMStorageManager.h"
 #include "nsJSON.h"
 #include "nsZipArchive.h"
-#include "mozIApplicationClearPrivateDataParams.h"
 #include "mozilla/Attributes.h"
 #include "mozilla/dom/DOMException.h"
 #include "mozilla/dom/DOMRequest.h"
diff --git a/layout/build/nsLayoutStatics.cpp b/layout/build/nsLayoutStatics.cpp
index ab6af2eb21..ffdf624e49 100644
--- a/layout/build/nsLayoutStatics.cpp
+++ b/layout/build/nsLayoutStatics.cpp
@@ -282,8 +282,6 @@ nsLayoutStatics::Initialize()
 #ifdef MOZ_PERMISSIONS
   nsPermissionManager::ClearOriginDataObserverInit();
 #endif
-  nsCookieService::AppClearDataObserverInit();
-  nsApplicationCacheService::AppClearDataObserverInit();
 
   HTMLVideoElement::Init();
 
diff --git a/netwerk/base/nsNetUtil.cpp b/netwerk/base/nsNetUtil.cpp
index b9a07f34a1..ce62cfa8fc 100644
--- a/netwerk/base/nsNetUtil.cpp
+++ b/netwerk/base/nsNetUtil.cpp
@@ -12,7 +12,6 @@
 #include "mozilla/Preferences.h"
 #include "nsNetUtil.h"
 #include "nsNetUtilInlines.h"
-#include "mozIApplicationClearPrivateDataParams.h"
 #include "nsCategoryCache.h"
 #include "nsContentUtils.h"
 #include "nsHashKeys.h"
@@ -1324,39 +1323,6 @@ NS_HasBeenCrossOrigin(nsIChannel* aChannel, bool aReport)
   return NS_FAILED(loadingPrincipal->CheckMayLoad(uri, aReport, dataInherits));
 }
 
-nsresult
-NS_GetAppInfoFromClearDataNotification(nsISupports *aSubject,
-                                       uint32_t *aAppID,
-                                       bool *aBrowserOnly)
-{
-    nsresult rv;
-
-    nsCOMPtr<mozIApplicationClearPrivateDataParams>
-        clearParams(do_QueryInterface(aSubject));
-    MOZ_ASSERT(clearParams);
-    if (!clearParams) {
-        return NS_ERROR_UNEXPECTED;
-    }
-
-    uint32_t appId;
-    rv = clearParams->GetAppId(&appId);
-    MOZ_ASSERT(NS_SUCCEEDED(rv));
-    MOZ_ASSERT(appId != NECKO_UNKNOWN_APP_ID);
-    NS_ENSURE_SUCCESS(rv, rv);
-    if (appId == NECKO_UNKNOWN_APP_ID) {
-        return NS_ERROR_UNEXPECTED;
-    }
-
-    bool browserOnly = false;
-    rv = clearParams->GetBrowserOnly(&browserOnly);
-    MOZ_ASSERT(NS_SUCCEEDED(rv));
-    NS_ENSURE_SUCCESS(rv, rv);
-
-    *aAppID = appId;
-    *aBrowserOnly = browserOnly;
-    return NS_OK;
-}
-
 bool
 NS_ShouldCheckAppCache(nsIURI *aURI, bool usePrivateBrowsing)
 {
diff --git a/netwerk/base/nsNetUtil.h b/netwerk/base/nsNetUtil.h
index 53fa679879..f9645f4c60 100644
--- a/netwerk/base/nsNetUtil.h
+++ b/netwerk/base/nsNetUtil.h
@@ -682,15 +682,6 @@ bool NS_GetAppInfo(nsIChannel *aChannel,
                    uint32_t *aAppID,
                    bool *aIsInIsolatedMozBrowserElement);
 
-/**
- *  Gets appId and browserOnly parameters from the TOPIC_WEB_APP_CLEAR_DATA
- *  nsIObserverService notification.  Used when clearing user data or
- *  uninstalling web apps.
- */
-nsresult NS_GetAppInfoFromClearDataNotification(nsISupports *aSubject,
-                                                uint32_t *aAppID,
-                                                bool *aBrowserOnly);
-
 /**
  * Determines whether appcache should be checked for a given URI.
  */
diff --git a/netwerk/cache/nsApplicationCacheService.cpp b/netwerk/cache/nsApplicationCacheService.cpp
index c512b91695..5420f2755f 100644
--- a/netwerk/cache/nsApplicationCacheService.cpp
+++ b/netwerk/cache/nsApplicationCacheService.cpp
@@ -7,7 +7,6 @@
 #include "nsCacheService.h"
 #include "nsApplicationCacheService.h"
 #include "nsCRT.h"
-#include "mozIApplicationClearPrivateDataParams.h"
 #include "nsNetCID.h"
 #include "nsNetUtil.h"
 #include "nsIObserverService.h"
@@ -253,14 +252,3 @@ private:
 NS_IMPL_ISUPPORTS(AppCacheClearDataObserver, nsIObserver)
 
 } // namespace
-
-// Instantiates and registers AppCacheClearDataObserver for notifications
-void
-nsApplicationCacheService::AppClearDataObserverInit()
-{
-  nsCOMPtr<nsIObserverService> observerService = services::GetObserverService();
-  if (observerService) {
-    RefPtr<AppCacheClearDataObserver> obs = new AppCacheClearDataObserver();
-    observerService->AddObserver(obs, "clear-origin-attributes-data", /*ownsWeak=*/ false);
-  }
-}
diff --git a/netwerk/cache/nsApplicationCacheService.h b/netwerk/cache/nsApplicationCacheService.h
index 73bd32206c..45623e50b9 100644
--- a/netwerk/cache/nsApplicationCacheService.h
+++ b/netwerk/cache/nsApplicationCacheService.h
@@ -18,8 +18,6 @@ public:
     NS_DECL_ISUPPORTS
     NS_DECL_NSIAPPLICATIONCACHESERVICE
 
-    static void AppClearDataObserverInit();
-
 private:
     ~nsApplicationCacheService();
     RefPtr<nsCacheService> mCacheService;
diff --git a/netwerk/cookie/nsCookieService.cpp b/netwerk/cookie/nsCookieService.cpp
index cc996a201a..9ffee5fa76 100644
--- a/netwerk/cookie/nsCookieService.cpp
+++ b/netwerk/cookie/nsCookieService.cpp
@@ -48,8 +48,6 @@
 #include "mozilla/storage.h"
 #include "mozilla/AutoRestore.h"
 #include "mozilla/FileUtils.h"
-#include "nsIAppsService.h"
-#include "mozIApplicationClearPrivateDataParams.h"
 #include "nsIConsoleService.h"
 #include "nsVariant.h"
 
@@ -674,15 +672,6 @@ nsCookieService::GetSingleton()
   return gCookieService;
 }
 
-/* static */ void
-nsCookieService::AppClearDataObserverInit()
-{
-  nsCOMPtr<nsIObserverService> observerService = services::GetObserverService();
-  nsCOMPtr<nsIObserver> obs = new AppClearDataObserver();
-  observerService->AddObserver(obs, TOPIC_CLEAR_ORIGIN_DATA,
-                               /* ownsWeak= */ false);
-}
-
 /******************************************************************************
  * nsCookieService impl:
  * public methods
diff --git a/netwerk/cookie/nsCookieService.h b/netwerk/cookie/nsCookieService.h
index deb9fed330..df83045243 100644
--- a/netwerk/cookie/nsCookieService.h
+++ b/netwerk/cookie/nsCookieService.h
@@ -260,14 +260,6 @@ class nsCookieService final : public nsICookieService
     static nsICookieService*      GetXPCOMSingleton();
     nsresult                      Init();
 
-  /**
-   * Start watching the observer service for messages indicating that an app has
-   * been uninstalled.  When an app is uninstalled, we get the cookie service
-   * (thus instantiating it, if necessary) and clear all the cookies for that
-   * app.
-   */
-  static void AppClearDataObserverInit();
-
   protected:
     virtual ~nsCookieService();
 
diff --git a/netwerk/ipc/NeckoParent.cpp b/netwerk/ipc/NeckoParent.cpp
index c3a288e689..3b00a15d29 100644
--- a/netwerk/ipc/NeckoParent.cpp
+++ b/netwerk/ipc/NeckoParent.cpp
@@ -34,7 +34,6 @@
 #include "mozilla/AppProcessChecker.h"
 #include "nsPrintfCString.h"
 #include "nsHTMLDNSPrefetch.h"
-#include "nsIAppsService.h"
 #include "nsEscape.h"
 #include "SerializedLoadContext.h"
 #include "nsAuthInformationHolder.h"
diff --git a/netwerk/protocol/http/nsHttpAuthCache.cpp b/netwerk/protocol/http/nsHttpAuthCache.cpp
index be5cd17a77..b5b6ee79f3 100644
--- a/netwerk/protocol/http/nsHttpAuthCache.cpp
+++ b/netwerk/protocol/http/nsHttpAuthCache.cpp
@@ -13,7 +13,6 @@
 #include "mozilla/Attributes.h"
 #include "nsString.h"
 #include "nsCRT.h"
-#include "mozIApplicationClearPrivateDataParams.h"
 #include "nsIObserverService.h"
 #include "mozilla/Services.h"
 #include "mozilla/DebugOnly.h"
diff --git a/netwerk/protocol/http/nsHttpHandler.cpp b/netwerk/protocol/http/nsHttpHandler.cpp
index 4e96415105..d6c5ca2107 100644
--- a/netwerk/protocol/http/nsHttpHandler.cpp
+++ b/netwerk/protocol/http/nsHttpHandler.cpp
@@ -33,7 +33,6 @@
 #include "nsSocketTransportService2.h"
 #include "nsAlgorithm.h"
 #include "ASpdySession.h"
-#include "mozIApplicationClearPrivateDataParams.h"
 #include "EventTokenBucket.h"
 #include "Tickler.h"
 #include "nsIXULAppInfo.h"
@@ -388,7 +387,6 @@ nsHttpHandler::Init()
         obsService->AddObserver(this, "net:prune-all-connections", true);
         obsService->AddObserver(this, "net:failed-to-process-uri-content", true);
         obsService->AddObserver(this, "last-pb-context-exited", true);
-        obsService->AddObserver(this, "webapps-clear-data", true);
         obsService->AddObserver(this, "browser:purge-session-history", true);
         obsService->AddObserver(this, NS_NETWORK_LINK_TOPIC, true);
         obsService->AddObserver(this, "application-background", true);
@@ -2173,10 +2171,6 @@ nsHttpHandler::Observe(nsISupports *subject,
         if (mConnMgr) {
             mConnMgr->ClearAltServiceMappings();
         }
-    } else if (!strcmp(topic, "webapps-clear-data")) {
-        if (mConnMgr) {
-            mConnMgr->ClearAltServiceMappings();
-        }
     } else if (!strcmp(topic, "browser:purge-session-history")) {
         if (mConnMgr) {
             if (gSocketTransportService) {
diff --git a/netwerk/protocol/wyciwyg/nsWyciwygProtocolHandler.cpp b/netwerk/protocol/wyciwyg/nsWyciwygProtocolHandler.cpp
index 4e1f7c22e6..3bf1fedf76 100644
--- a/netwerk/protocol/wyciwyg/nsWyciwygProtocolHandler.cpp
+++ b/netwerk/protocol/wyciwyg/nsWyciwygProtocolHandler.cpp
@@ -11,7 +11,6 @@
 #include "nsServiceManagerUtils.h"
 #include "plstr.h"
 #include "nsIObserverService.h"
-#include "mozIApplicationClearPrivateDataParams.h"
 #include "nsIURI.h"
 
 #include "mozilla/net/NeckoChild.h"
diff --git a/testing/specialpowers/content/SpecialPowersObserver.jsm b/testing/specialpowers/content/SpecialPowersObserver.jsm
index fc7584505e..0b44393fb9 100644
--- a/testing/specialpowers/content/SpecialPowersObserver.jsm
+++ b/testing/specialpowers/content/SpecialPowersObserver.jsm
@@ -87,7 +87,6 @@ SpecialPowersObserver.prototype._loadFrameScript = function()
     this._messageManager.addMessageListener("SPUnloadExtension", this);
     this._messageManager.addMessageListener("SPExtensionMessage", this);
     this._messageManager.addMessageListener("SPCleanUpSTSData", this);
-    this._messageManager.addMessageListener("SPClearAppPrivateData", this);
 
     this._messageManager.loadFrameScript(CHILD_LOGGER_SCRIPT, true);
     this._messageManager.loadFrameScript(CHILD_SCRIPT_API, true);
@@ -159,7 +158,6 @@ SpecialPowersObserver.prototype.uninit = function()
     this._messageManager.removeMessageListener("SPUnloadExtension", this);
     this._messageManager.removeMessageListener("SPExtensionMessage", this);
     this._messageManager.removeMessageListener("SPCleanUpSTSData", this);
-    this._messageManager.removeMessageListener("SPClearAppPrivateData", this);
 
     this._messageManager.removeDelayedFrameScript(CHILD_LOGGER_SCRIPT);
     this._messageManager.removeDelayedFrameScript(CHILD_SCRIPT_API);
diff --git a/testing/specialpowers/content/SpecialPowersObserverAPI.js b/testing/specialpowers/content/SpecialPowersObserverAPI.js
index f37f7bf0e9..d3137a42d4 100644
--- a/testing/specialpowers/content/SpecialPowersObserverAPI.js
+++ b/testing/specialpowers/content/SpecialPowersObserverAPI.js
@@ -601,28 +601,6 @@ SpecialPowersObserverAPI.prototype = {
         return undefined;
       }
 
-      case "SPClearAppPrivateData": {
-        let appId = aMessage.data.appId;
-        let browserOnly = aMessage.data.browserOnly;
-
-        let attributes = { appId: appId };
-        if (browserOnly) {
-          attributes.inIsolatedMozBrowser = true;
-        }
-        this._notifyCategoryAndObservers(null,
-                                         "clear-origin-attributes-data",
-                                         JSON.stringify(attributes));
-
-        let subject = {
-          appId: appId,
-          browserOnly: browserOnly,
-          QueryInterface: XPCOMUtils.generateQI([Ci.mozIApplicationClearPrivateDataParams])
-        };
-        this._notifyCategoryAndObservers(subject, "webapps-clear-data", null);
-
-        return undefined;
-      }
-
       default:
         throw new SpecialPowersError("Unrecognized Special Powers API");
     }
diff --git a/testing/specialpowers/content/specialpowers.js b/testing/specialpowers/content/specialpowers.js
index 09dbb52097..dae8584690 100644
--- a/testing/specialpowers/content/specialpowers.js
+++ b/testing/specialpowers/content/specialpowers.js
@@ -44,8 +44,7 @@ function SpecialPowers(window) {
                             "SPLoadExtension",
                             "SPStartupExtension",
                             "SPUnloadExtension",
-                            "SPExtensionMessage",
-                            "SPClearAppPrivateData"];
+                            "SPExtensionMessage"];
   addMessageListener("SPPingService", this._messageListener);
   addMessageListener("SpecialPowers.FilesCreated", this._messageListener);
   addMessageListener("SpecialPowers.FilesError", this._messageListener);
diff --git a/testing/specialpowers/content/specialpowersAPI.js b/testing/specialpowers/content/specialpowersAPI.js
index e97ad89c40..dc33cd8260 100644
--- a/testing/specialpowers/content/specialpowersAPI.js
+++ b/testing/specialpowers/content/specialpowersAPI.js
@@ -1766,16 +1766,6 @@ SpecialPowersAPI.prototype = {
       // It's an URL.
       let uri = Services.io.newURI(arg, null, null);
       principal = secMan.createCodebasePrincipal(uri, {});
-    } else if (arg.manifestURL) {
-      // It's a thing representing an app.
-      let appsSvc = Cc["@mozilla.org/AppsService;1"]
-                      .getService(Ci.nsIAppsService)
-      let app = appsSvc.getAppByManifestURL(arg.manifestURL);
-      if (!app) {
-        throw "No app for this manifest!";
-      }
-
-      principal = app.principal;
     } else if (arg.nodePrincipal) {
       // It's a document.
       // In some tests the arg is a wrapped DOM element, so we unwrap it first.
diff --git a/tools/lint/eslint/modules.json b/tools/lint/eslint/modules.json
index 1ff5469789..78efc21a2a 100644
--- a/tools/lint/eslint/modules.json
+++ b/tools/lint/eslint/modules.json
@@ -11,7 +11,6 @@
   "AlertsHelper.jsm": [],
   "AppData.jsm": ["makeFakeAppDir"],
   "AppInfo.jsm": ["newAppInfo", "getAppInfo", "updateAppInfo"],
-  "AppsServiceChild.jsm": ["DOMApplicationRegistry", "WrappedManifestCache"],
   "arrays.js": ["inArray", "getSet", "indexOf", "remove", "rindexOf", "compare"],
   "assertions.js": ["Assert", "Expect"],
   "async.js": ["Async"],