VideoSurfaceLayer: submit empty CompositorFrame before stopping frame submission.

This leads to better memory performance as the last frame will be discarded.

Bug: 829813
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I7bc753e7e8d74d80d8c8390bd0f33ed45003ed5a
Reviewed-on: https://chromium-review.googlesource.com/1141291
Commit-Queue: Mounir Lamouri <mlamouri@chromium.org>
Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Reviewed-by: enne <enne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#576331}

third_party/blink/renderer/platform/graphics/video_frame_submitter.cc

@@ -71,6 +71,8 @@ void VideoFrameSubmitter::UpdateSubmissionStateInternal() {
     compositor_frame_sink_->SetNeedsBeginFrame(is_rendering_ && should_submit_);
     if (should_submit_)
       SubmitSingleFrame();
+    else if (!frame_size_.IsEmpty())
+      SubmitEmptyFrame();
   }
 }
 
@@ -194,11 +196,15 @@ void VideoFrameSubmitter::SubmitFrame(
   if (!compositor_frame_sink_ || !should_submit_)
     return;
 
+  // TODO(mlamouri): the `frame_size_` is expected to be consistent but seems to
+  // change in some cases. Ideally, it should be set when empty and a DCHECK
+  // should make sure it stays consistent.
+  frame_size_ = gfx::Rect(video_frame->coded_size());
+
   viz::CompositorFrame compositor_frame;
   std::unique_ptr<viz::RenderPass> render_pass = viz::RenderPass::Create();
 
-  render_pass->SetNew(1, gfx::Rect(video_frame->coded_size()),
-                      gfx::Rect(video_frame->coded_size()), gfx::Transform());
+  render_pass->SetNew(1, frame_size_, frame_size_, gfx::Transform());
   render_pass->filters = cc::FilterOperations();
   resource_provider_->AppendQuads(render_pass.get(), video_frame, rotation_);
   compositor_frame.metadata.begin_frame_ack = begin_frame_ack;
@@ -225,6 +231,28 @@ void VideoFrameSubmitter::SubmitFrame(
   waiting_for_compositor_ack_ = true;
 }
 
+void VideoFrameSubmitter::SubmitEmptyFrame() {
+  TRACE_EVENT0("media", "VideoFrameSubmitter::SubmitEmptyFrame");
+  DCHECK_CALLED_ON_VALID_THREAD(media_thread_checker_);
+  DCHECK(compositor_frame_sink_ && !should_submit_);
+  DCHECK(!frame_size_.IsEmpty());
+
+  viz::CompositorFrame compositor_frame;
+
+  compositor_frame.metadata.begin_frame_ack =
+      viz::BeginFrameAck::CreateManualAckWithDamage();
+  compositor_frame.metadata.device_scale_factor = 1;
+  compositor_frame.metadata.may_contain_video = true;
+
+  std::unique_ptr<viz::RenderPass> render_pass = viz::RenderPass::Create();
+  render_pass->SetNew(1, frame_size_, frame_size_, gfx::Transform());
+  compositor_frame.render_pass_list.push_back(std::move(render_pass));
+
+  compositor_frame_sink_->SubmitCompositorFrame(
+      surface_id_.local_surface_id(), std::move(compositor_frame), nullptr, 0);
+  waiting_for_compositor_ack_ = true;
+}
+
 void VideoFrameSubmitter::OnBeginFrame(const viz::BeginFrameArgs& args) {
   TRACE_EVENT0("media", "VideoFrameSubmitter::OnBeginFrame");
   DCHECK_CALLED_ON_VALID_THREAD(media_thread_checker_);

third_party/blink/renderer/platform/graphics/video_frame_submitter.h

@@ -92,6 +92,7 @@ class PLATFORM_EXPORT VideoFrameSubmitter
   void StartSubmitting();
   void UpdateSubmissionStateInternal();
   void SubmitFrame(const viz::BeginFrameAck&, scoped_refptr<media::VideoFrame>);
+  void SubmitEmptyFrame();
 
   // Pulls frame and submits it to compositor.
   // Used in cases like PaintSingleFrame, which occurs before video rendering
@@ -114,6 +115,11 @@ class PLATFORM_EXPORT VideoFrameSubmitter
   bool should_submit_ = false;
   media::VideoRotation rotation_;
 
+  // Size of the video frame being submitted. It is set the first time a frame
+  // is submitted and is expected to never change aftewards. Used to send an
+  // empty frame when the video is out of view.
+  gfx::Rect frame_size_;
+
   THREAD_CHECKER(media_thread_checker_);
 
   base::WeakPtrFactory<VideoFrameSubmitter> weak_ptr_factory_;

third_party/blink/renderer/platform/graphics/video_frame_submitter_test.cc

@@ -287,7 +287,7 @@ TEST_F(VideoFrameSubmitterTest, ShouldSubmitPreventsSubmission) {
       .WillOnce(Return(media::VideoFrame::CreateFrame(
           media::PIXEL_FORMAT_YV12, gfx::Size(8, 8), gfx::Rect(gfx::Size(8, 8)),
           gfx::Size(8, 8), base::TimeDelta())));
-  EXPECT_CALL(*sink_, DoSubmitCompositorFrame(_, _));
+  EXPECT_CALL(*sink_, DoSubmitCompositorFrame(_, _)).Times(1);
   EXPECT_CALL(*provider_, PutCurrentFrame());
   EXPECT_CALL(*resource_provider_, AppendQuads(_, _, _));
   EXPECT_CALL(*resource_provider_, PrepareSendToParent(_, _));
@@ -296,6 +296,8 @@ TEST_F(VideoFrameSubmitterTest, ShouldSubmitPreventsSubmission) {
   scoped_task_environment_.RunUntilIdle();
 
   EXPECT_CALL(*sink_, SetNeedsBeginFrame(false));
+  EXPECT_CALL(*sink_, DoSubmitCompositorFrame(_, _)).Times(1);
+  EXPECT_CALL(*provider_, GetCurrentFrame()).Times(0);
   submitter_->UpdateSubmissionState(false);
   scoped_task_environment_.RunUntilIdle();