Bug 1313548: P1. Always resolve waiting promise, when clearing waitforkey. r=gerald

MozReview-Commit-ID: 6xu8Rcn9WMO

--HG--
extra : rebase_source : 54f99f2d4fc6370ee64a6e3dc0bec69f5edc9085

dom/media/MediaFormatReader.cpp

@@ -2279,14 +2279,10 @@ MediaFormatReader::Update(TrackType aTrack)
     return;
   }
 
-  if (decoder.mWaitingForKey) {
-    decoder.mWaitingForKey = false;
-    if (decoder.HasWaitingPromise() && !decoder.IsWaiting()) {
+  if (decoder.CancelWaitingForKey()) {
     LOGV("No longer waiting for key. Resolving waiting promise");
-      decoder.mWaitingPromise.Resolve(decoder.mType, __func__);
     return;
   }
-  }
 
   if (!needInput) {
     LOGV("No need for additional input (pending:%u)",

dom/media/MediaFormatReader.h

@@ -349,6 +349,7 @@ private:
       mDecodeRequest.DisconnectIfExists();
       mDrainRequest.DisconnectIfExists();
       mDrainState = DrainState::None;
+      CancelWaitingForKey();
       mOutput.Clear();
       mNumSamplesInput = 0;
       mNumSamplesOutput = 0;
@@ -381,6 +382,19 @@ private:
       mFlushed = true;
     }
 
+    bool CancelWaitingForKey()
+    {
+      if (!mWaitingForKey) {
+        return false;
+      }
+      mWaitingForKey = false;
+      if (IsWaiting() || mWaitingPromise.IsEmpty()) {
+        return false;
+      }
+      mWaitingPromise.Resolve(mType, __func__);
+      return true;
+    }
+
     // Reset the state of the DecoderData, clearing all queued frames
     // (pending demuxed and decoded).
     // The track demuxer is *not* reset.
@@ -389,11 +403,11 @@ private:
       MOZ_ASSERT(mOwner->OnTaskQueue());
       mDemuxEOS = false;
       mWaitingForData = false;
-      mWaitingForKey = false;
       mQueuedSamples.Clear();
       mDecodeRequest.DisconnectIfExists();
       mDrainRequest.DisconnectIfExists();
       mDrainState = DrainState::None;
+      CancelWaitingForKey();
       mTimeThreshold.reset();
       mLastSampleTime.reset();
       mOutput.Clear();