DirectCompositorFrameSink Uses CompositorFrameSinkSupport

content/browser/renderer_host/compositor_impl_android.cc

Index: content/browser/renderer_host/compositor_impl_android.cc
diff --git a/content/browser/renderer_host/compositor_impl_android.cc b/content/browser/renderer_host/compositor_impl_android.cc
index 752f72344cfa462ec18928f2ab52ce6e54a1641c..5935cdf35c47dcb025d88afa2421e3a5fadb4466 100644
--- a/content/browser/renderer_host/compositor_impl_android.cc
+++ b/content/browser/renderer_host/compositor_impl_android.cc
@@ -466,6 +466,7 @@ void CompositorImpl::SetVisible(bool visible) {
 
     host_->SetVisible(false);
     host_->ReleaseCompositorFrameSink();
+    has_compositor_frame_sink_ = false;
     pending_swapbuffers_ = 0;
     display_.reset();
   } else {
@@ -531,7 +532,12 @@ void CompositorImpl::RequestNewCompositorFrameSink() {
 }
 
 void CompositorImpl::DidInitializeCompositorFrameSink() {
-  compositor_frame_sink_request_pending_ = false;
+  compositor_frame_sink_request_pending_ = true;
+  has_compositor_frame_sink_ = true;
+  for (auto& frame_sink_id : pending_child_frame_sink_ids_) {
+    AddChildFrameSink(frame_sink_id);
+  }
+  pending_child_frame_sink_ids_.clear();
 }
 
 void CompositorImpl::DidFailToInitializeCompositorFrameSink() {
@@ -671,7 +677,6 @@ void CompositorImpl::InitializeDisplay(
                 frame_sink_id_, manager, display_.get(), context_provider,
                 nullptr, BrowserGpuMemoryBufferManager::current(),
                 HostSharedBitmapManager::current());
-
   display_->SetVisible(true);
   display_->Resize(size_);
   host_->SetCompositorFrameSink(std::move(compositor_frame_sink));
@@ -706,6 +711,7 @@ void CompositorImpl::DidReceiveCompositorFrameAck() {
 
 void CompositorImpl::DidLoseCompositorFrameSink() {
   TRACE_EVENT0("compositor", "CompositorImpl::DidLoseCompositorFrameSink");
+  has_compositor_frame_sink_ = false;
   client_->OnSwapBuffersCompleted(0);
 }
 
@@ -735,6 +741,19 @@ cc::FrameSinkId CompositorImpl::GetFrameSinkId() {
   return frame_sink_id_;
 }
 
+void CompositorImpl::AddChildFrameSink(cc::FrameSinkId frame_sink_id) {
+  if (!has_compositor_frame_sink_) {

[boliu, 2017/01/27 23:17:59]

reverse the the condition and flip the body, it's eaiser to read

[Alex Z., 2017/01/29 14:58:51]

Done.

+    pending_child_frame_sink_ids_.insert(frame_sink_id);
+  } else {
+    // All pending child frame sink ids should be added upon the creation of
+    // compositor frame sink.
+    DCHECK(pending_child_frame_sink_ids_.empty());

[boliu, 2017/01/27 23:17:59]

this DCHECK clearly doesn't hold when called from
DidInitializeCompositorFrameSink

[Alex Z., 2017/01/29 14:58:51]

My bad. I was thinking of two ways to approach this
and got mixed.
It's removed.

+    ui::ContextProviderFactory::GetInstance()
+        ->GetSurfaceManager()
+        ->RegisterFrameSinkHierarchy(frame_sink_id_, frame_sink_id);

[boliu, 2017/01/27 23:17:59]

it's not immediately clear to me why this can't be called when there is no frame
sink for this compositor?

[Alex Z., 2017/01/29 14:58:51]

~CompositorFrameSinkSupport() calls InvalidateFrameSinkId(). The FrameSinkId 
will be invalid until a DirectCompositorFrameSink is attached again.

+  }
+}
+
 bool CompositorImpl::HavePendingReadbacks() {
   return !readback_layer_tree_->children().empty();
 }