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

- bug 1191889 skip Close() when not initialized r=roc (9bbb78c01e)
- Bug 1175319 - Remove outdated MDSM documenation. r=jya DONTBUILD (775d7b1cb4)
- Bug 1265978. Part 1 - add mozDumpDebugInfo() to HTMLMediaElement.webidl. r=bz. (6518ad6a08)
- Bug 1265978. Part 2 - add methods to MediaDecoder and MDSM to dump debugging info. r=jya. (1b8ad138c8)
- Bug 1265978. Part 2.5 - also dump reader data. r=jya. (d866537269)
- Bug 1265978. Part 3 - invoke mozDumpDebugInfo() from JS. r=jya. (7a5a7b5837)

dom/media/MediaDecoderStateMachine.cpp

@@ -63,6 +63,7 @@ using namespace mozilla::media;
 #undef LOG
 #undef DECODER_LOG
 #undef VERBOSE_LOG
+#undef DUMP_LOG
 
 #define LOG(m, l, x, ...) \
   MOZ_LOG(m, l, ("Decoder=%p " x, mDecoderID, ##__VA_ARGS__))
@@ -79,6 +80,9 @@ using namespace mozilla::media;
 #define DECODER_WARN(x, ...) \
   DECODER_WARN_HELPER(0, (nsPrintfCString("Decoder=%p " x, mDecoderID, ##__VA_ARGS__).get()))
 
+#define DUMP_LOG(x, ...) \
+  NS_DebugBreak(NS_DEBUG_WARNING, nsPrintfCString("Decoder=%p " x, mDecoderID, ##__VA_ARGS__).get(), nullptr, nullptr, -1)
+
 // Certain constants get stored as member variables and then adjusted by various
 // scale factors on a per-decoder basis. We want to make sure to avoid using these
 // constants directly, so we put them in a namespace.
@@ -2867,6 +2871,28 @@ uint32_t MediaDecoderStateMachine::GetAmpleVideoFrames() const
     : std::max<uint32_t>(sVideoQueueDefaultSize, MIN_VIDEO_QUEUE_SIZE);
 }
 
+void
+MediaDecoderStateMachine::DumpDebugInfo()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+
+  // It is fine to capture a raw pointer here because MediaDecoder only call
+  // this function before shutdown begins.
+  nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction([this] () {
+    DUMP_LOG(
+      "GetMediaTime=%lld GetClock=%lld "
+      "mState=%s mPlayState=%d mDecodingFirstFrame=%d IsPlaying=%d "
+      "mAudioStatus=%s mVideoStatus=%s mDecodedAudioEndTime=%lld mDecodedVideoEndTime=%lld "
+      "mIsAudioPrerolling=%d mIsVideoPrerolling=%d",
+      GetMediaTime(), mMediaSink->IsStarted() ? GetClock() : -1,
+      gMachineStateStr[mState], mPlayState.Ref(), mDecodingFirstFrame, IsPlaying(),
+      AudioRequestStatus(), VideoRequestStatus(), mDecodedAudioEndTime, mDecodedVideoEndTime,
+      mIsAudioPrerolling, mIsVideoPrerolling);
+  });
+
+  OwnerThread()->DispatchStateChange(r.forget());
+}
+
 void MediaDecoderStateMachine::AddOutputStream(ProcessedMediaStream* aStream,
                                                bool aFinishWhenEnded)
 {