Revert incorrect UAO optimization that broke SSUAO

netwerk/protocol/http/nsHttpChannel.cpp

@@ -6031,8 +6031,6 @@ nsHttpChannel::BeginConnect()
     // notify "http-on-modify-request" observers
     CallOnModifyRequestObservers();
 
-    SetLoadGroupUserAgentOverride();
-
     // Check if request was cancelled during on-modify-request or on-useragent.
     if (mCanceled) {
         return mStatus;
@@ -8399,50 +8397,6 @@ nsHttpChannel::MaybeWarnAboutAppCache()
     }
 }
 
-void
-nsHttpChannel::SetLoadGroupUserAgentOverride()
-{
-    nsCOMPtr<nsIURI> uri;
-    GetURI(getter_AddRefs(uri));
-    nsAutoCString uriScheme;
-    if (uri) {
-        uri->GetScheme(uriScheme);
-    }
-
-    // We don't need a UA for file: protocols.
-    if (uriScheme.EqualsLiteral("file")) {
-        gHttpHandler->OnUserAgentRequest(this);
-        return;
-    }
-
-    nsIRequestContextService* rcsvc = gHttpHandler->GetRequestContextService();
-    nsCOMPtr<nsIRequestContext> rc;
-    if (rcsvc) {
-        rcsvc->GetRequestContext(mRequestContextID,
-                                    getter_AddRefs(rc));
-    }
-
-    nsAutoCString ua;
-    if (nsContentUtils::IsNonSubresourceRequest(this)) {
-        gHttpHandler->OnUserAgentRequest(this);
-        if (rc) {
-            GetRequestHeader(NS_LITERAL_CSTRING("User-Agent"), ua);
-            rc->SetUserAgentOverride(ua);
-        }
-    } else {
-        GetRequestHeader(NS_LITERAL_CSTRING("User-Agent"), ua);
-        // Don't overwrite the UA if it is already set (eg by an XHR with explicit UA).
-        if (ua.IsEmpty()) {
-            if (rc) {
-                rc->GetUserAgentOverride(ua);
-                SetRequestHeader(NS_LITERAL_CSTRING("User-Agent"), ua, false);
-            } else {
-                gHttpHandler->OnUserAgentRequest(this);
-            }
-        }
-    }
-}
-
 void
 nsHttpChannel::SetDoNotTrack()
 {