Bug 1521964 - Don't suspend the video decoder when cloning a video visually. r=jya

Differential Revision: https://phabricator.services.mozilla.com/D20674

--HG--
extra : moz-landing-system : lando

dom/html/HTMLVideoElement.cpp

@@ -471,6 +471,7 @@ void HTMLVideoElement::MaybeBeginCloningVisually() {
         mVisualCloneTarget->GetVideoFrameContainer();
     if (mdsm && container) {
       mdsm->SetSecondaryVideoContainer(container);
+      mDecoder->SetCloningVisually(true);
     }
   } else if (mSrcStream) {
     VideoFrameContainer* container =
@@ -488,6 +489,7 @@ void HTMLVideoElement::EndCloningVisually() {
     MediaDecoderStateMachine* mdsm = mDecoder->GetStateMachine();
     if (mdsm) {
       mdsm->SetSecondaryVideoContainer(nullptr);
+      mDecoder->SetCloningVisually(false);
     }
   } else if (mSrcStream) {
     VideoFrameContainer* container =

dom/media/MediaDecoder.cpp

@@ -305,6 +305,7 @@ MediaDecoder::MediaDecoder(MediaDecoderInit& aInit)
       mIsElementInTree(false),
       mForcedHidden(false),
       mHasSuspendTaint(aInit.mHasSuspendTaint),
+      mIsCloningVisually(false),
       mPlaybackRate(aInit.mPlaybackRate),
       mLogicallySeeking(false, "MediaDecoder::mLogicallySeeking"),
       INIT_MIRROR(mBuffered, TimeIntervals()),
@@ -988,6 +989,14 @@ void MediaDecoder::UpdateVideoDecodeMode() {
     return;
   }
 
+  // If mIsCloningVisually is set, never suspend the video decoder.
+  if (mIsCloningVisually) {
+    LOG("UpdateVideoDecodeMode(), set Normal because the element is cloning "
+        "itself visually to another video container.");
+    mDecoderStateMachine->SetVideoDecodeMode(VideoDecodeMode::Normal);
+    return;
+  }
+
   // Don't suspend elements that is not in tree.
   if (!mIsElementInTree) {
     LOG("UpdateVideoDecodeMode(), set Normal because the element is not in "
@@ -1046,6 +1055,13 @@ bool MediaDecoder::HasSuspendTaint() const {
   return mHasSuspendTaint;
 }
 
+void MediaDecoder::SetCloningVisually(bool aIsCloningVisually) {
+  if (mIsCloningVisually != aIsCloningVisually) {
+    mIsCloningVisually = aIsCloningVisually;
+    UpdateVideoDecodeMode();
+  }
+}
+
 bool MediaDecoder::IsMediaSeekable() {
   MOZ_ASSERT(NS_IsMainThread());
   NS_ENSURE_TRUE(GetStateMachine(), false);

dom/media/MediaDecoder.h

@@ -308,6 +308,8 @@ class MediaDecoder : public DecoderDoctorLifeLogger<MediaDecoder> {
   // Returns true if the decoder can't participate in suspend-video-decoder.
   bool HasSuspendTaint() const;
 
+  void SetCloningVisually(bool aIsCloningVisually);
+
   void UpdateVideoDecodeMode();
 
   void SetIsBackgroundVideoDecodingAllowed(bool aAllowed);
@@ -562,6 +564,10 @@ class MediaDecoder : public DecoderDoctorLifeLogger<MediaDecoder> {
   // disabled.
   bool mHasSuspendTaint;
 
+  // True if the decoder is sending video to a secondary container, and should
+  // not suspend the decoder.
+  bool mIsCloningVisually;
+
   MediaDecoderOwner::NextFrameStatus mNextFrameStatus =
       MediaDecoderOwner::NEXT_FRAME_UNAVAILABLE;