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

- Bug 1259678 - Refactor SubjectToCSP to avoid calling ShouldLoad if CSP doesn't apply to the content type. r=ckerschb (73d79be6f9)
- Bug 908933 - Part1 - CSP: Call ShouldLoad inside ShouldProcess for TYPE_OBJECT. r=ckerschb (eb87244649)
- Bug 1263790 - Resource timing initiatorType should be "iframe" instead of "subdocument" r=bz (e38569e488)
- Bug 1257809 - "Improve telemetry for PR_Connect". r=mcmanus (225fc45f80)
- Bug 698882 - mozilla::net::PollableEvent r=dragana r=mayhemer (abf47e4653)
- Bug 1260218 - SocketTransportService socket expansion r=dragana (6045e8d1a4)
- align comment (4b4cb6ac97)
- Bug 1253711 - delete unused MediaFormatReader::ByteInterval typedef; r=jya (b66387bb4f)
- Bug 1265974 - Don't fire push events in MediaQueue::PushFront(). r=jya. (f5caa8dcd4)
- Bug 1265969 - Don't fire pop events in MediaQueue::Reset(). r=jya. (601f546522)
- Bug 1250934: Don't reopen input AudioCallbackDrivers on a second use r=padenot (a5beb7ad31)
- Bug 1246310 - Resample the AudioSegment in SourceMediaStream::AddAudioTrack. r=padenot (bd3964f725)
- Bug 1239911 - Remove unused |mAudioChannel|. r=bechen. (8ba8408728)
- Bug 1250934: remove unused method from MediaStreamGraphImpl r=padenot (5d5767a14f)
- Bug 1199069 - Remove ancient deopt from AudioStream required for MSVC2010. r=jwwang (73b4390bfa)
- Bug 1229256: P1. Only check readyState update upon buffered range completion. r=jwwang (189ea2bd9e)
- Bug 1242338 - fix numerical issue in MediaDecoder::Seek(); r=jwwang (fa45e4bc4a)
- part of Bug 1158448 Part 2 (ee6f4fb502)
- Bug 1266680 - Fix stopping MediaStreamTrack when there are clones. r=jib (ffc225f820)
- Bug 1252459 - Replaced 'identity.name' by 'name' to fix identity undefined bug, r=mt (cc105ed048)
- Bug 1213056 - change getStats to be maplike. r=bz (95cadfa385)
- Bug 1259728 - minimal fix for reentrancy in pc.close(). r=jesup (56f8f5945e)
- Bug 1257100 - Report we can play type 'audio/mp4; codecs=mp4a.40.29'. r=jya (dbc04361a6)
- align some media tests (dfd85dfa34)

docshell/base/nsDocShell.cpp

@@ -10989,8 +10989,13 @@ nsDocShell::DoURILoad(nsIURI* aURI,
   nsCOMPtr<nsITimedChannel> timedChannel(do_QueryInterface(channel));
   if (timedChannel) {
     timedChannel->SetTimingEnabled(true);
-    if (IsFrame()) {
-      timedChannel->SetInitiatorType(NS_LITERAL_STRING("subdocument"));
+
+    nsCOMPtr<nsPIDOMWindow> win = GetWindow();
+    if (IsFrame() && win) {
+      nsCOMPtr<Element> frameElement = win->GetFrameElementInternal();
+      if (frameElement) {
+        timedChannel->SetInitiatorType(frameElement->LocalName());
+      }
     }
   }