import changes from `dev' branch of rmottola/Arctic-Fox:

- Bug 1169044 - Patch 1 - Refactor setting referrer and referrer policy between fetch and XHR. r=khuey (3912ebaef)
- Bug 1150771 - Let ArrayBuffer through object Xrays. r=gabor (bed760277)
- Bug 1151385 - Fail early for cross-origin sandboxPrototype. r=gabor (3b65b1561)
- Bug 1131707 - Transparently forward the construct bit for function forwarders. r=gabor (1f5792775)
- Bug 1170311 - Stop asserting non-null argument to nsIPrincipal::{subsumes,equals}{,ConsideringDomain}. r=gabor (7e36d6683)
- Bug 1171175 - Improve BasePrincipal::IsCodebasePrincipal. r=baku (0d278e8f4)
- Bug 1174731 - patch 1 - Make searchParams attribute readonly, r=smaug (11f5d6dcf)
- Bug 1174731 - patch 2 - Make searchParams attribute readonly, r=annevk (4aa7ea1e4)
- Bug 1170097 - Part 1: Move OriginAttributeDictionary. r=bholley (63a1139dd)
- Bug 1084525 - Part 1: Create initial PromisesActor skeleton r=fitzgen (2ef0ad37d)
- Bug 1131643 - Implement a Location object;r=jlong (710fb9b79)
- Bug 1129834 - Store BreakpointActors by original location;r=jlong (67d16d37a)
- Bug 1129837 - Remove generatedLocation from BreakpointActor;r=jlongster (018a60746)
- Bug 1082837 - test cases for image redirects loaded from the imagelib cache. r=smaug, ckerschb (49d216725)
- Bug 1073352, part 2 - Enable some devtools tests. r=ejpbruel (0de7cfdc0)
- Bug 1131646 - Clean up the breakpoint code;r=jlongster (7fa9c6a76)
- Bug 1136146 - Merge the latest version of the source-map library with fx-team;r=fitzgen (983f2c2e9)
- Bug 1042976 follow up - Remove getInnerId from script actors; r=Mossop (43f935298)
- Bug 837630 - Stop hiding __proto__ from O.getOwnPropertyNames. r=Waldo,peterv,past (0f321614d)
- Bug 1138975 - Refactor breakpoint sliding for non-source mapped sources;r=jlong (9fd4be4e4)
- Fix breaking on the "load" event in the debugger (bug 1054159). r=ochameau (6b6b40e78)
- Bug 983469 - Pause on breakpoint condition exception. r=fitzgen (fb6dfab57)
- Bug 1135435 - Add UI for breakpoint condition throws. r=fitzgen (b2f49cb03)
- Bug 1137384 - Rename ThreadSources as TabSources and move it up into the TabActor. r=ejpbruel (fdf1db5d9)

dom/fetch/FetchDriver.cpp

@@ -416,21 +416,37 @@ FetchDriver::HttpFetch(bool aCORSFlag, bool aCORSPreflightFlag, bool aAuthentica
     // Step 2. Set the referrer.
     nsAutoString referrer;
     mRequest->GetReferrer(referrer);
-    // The referrer should have already been resolved to a URL by the caller.
-    MOZ_ASSERT(!referrer.EqualsLiteral(kFETCH_CLIENT_REFERRER_STR));
-    if (!referrer.IsEmpty()) {
-      nsCOMPtr<nsIURI> refURI;
-      rv = NS_NewURI(getter_AddRefs(refURI), referrer, nullptr, nullptr);
+    if (referrer.EqualsLiteral(kFETCH_CLIENT_REFERRER_STR)) {
+      rv = nsContentUtils::SetFetchReferrerURIWithPolicy(mPrincipal,
+                                                         mDocument,
+                                                         httpChan);
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return FailWithNetworkError();
+      }
+    } else if (referrer.IsEmpty()) {
+      rv = httpChan->SetReferrerWithPolicy(nullptr, net::RP_No_Referrer);
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return FailWithNetworkError();
+      }
+    } else {
+      // From "Determine request's Referrer" step 3
+      // "If request's referrer is a URL, let referrerSource be request's
+      // referrer."
+      //
+      // This allows ServiceWorkers to function transparently when the referrer
+      // of the intercepted request is already set.
+      nsCOMPtr<nsIURI> referrerURI;
+      rv = NS_NewURI(getter_AddRefs(referrerURI), referrer, nullptr, nullptr);
       if (NS_WARN_IF(NS_FAILED(rv))) {
         return FailWithNetworkError();
       }
 
-      net::ReferrerPolicy referrerPolicy = net::RP_Default;
-      if (mDocument) {
-        referrerPolicy = mDocument->GetReferrerPolicy();
-      }
-
-      rv = httpChan->SetReferrerWithPolicy(refURI, referrerPolicy);
+      // FIXME(nsm): Can we assert that this case can only happen in
+      // ServiceWorkers and assume null mDocument?
+      rv =
+        httpChan->SetReferrerWithPolicy(nullptr,
+                                        mDocument ? mDocument->GetReferrerPolicy() :
+                                                    net::RP_Default);
       if (NS_WARN_IF(NS_FAILED(rv))) {
         return FailWithNetworkError();
       }