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..26c011a65f829872968707a14996ffa11c8b3c21 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;

[boliu, 2017/01/26 22:39:41]

why set this to false here?

[Alex Z., 2017/01/27 20:27:02]

host_->ReleaseCompositorFrameSink() calls
DirectCompositorFrameSink::DetachFromClient().
DetachFromClient() destroys CompositorFrameSinkSupport().
The frame_sink_id is invalidated in ~CompositorFrameSinkSupport().

     pending_swapbuffers_ = 0;
     display_.reset();
   } else {
@@ -532,6 +533,11 @@ void CompositorImpl::RequestNewCompositorFrameSink() {
 
 void CompositorImpl::DidInitializeCompositorFrameSink() {
   compositor_frame_sink_request_pending_ = false;
+  for (auto& frame_sink_id : pending_child_frame_sink_ids_) {
+    AddChildFrameSink(frame_sink_id);

[boliu, 2017/01/26 22:39:41]

this makes no sense to me.. has_compositor_frame_sink_ is probably still false
at this point? then this loop does absolutely nothing, in fact, I think it's an
infinite loop right here?

[Alex Z., 2017/01/27 20:27:02]

My bad. has_compositor_frame_sink_ should be set to true before the loop.

+  }
+  pending_child_frame_sink_ids_.clear();
+  has_compositor_frame_sink_ = true;
 }
 
 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_) {
+    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());
+    ui::ContextProviderFactory::GetInstance()
+        ->GetSurfaceManager()
+        ->RegisterFrameSinkHierarchy(frame_sink_id_, frame_sink_id);
+  }
+}
+
 bool CompositorImpl::HavePendingReadbacks() {
   return !readback_layer_tree_->children().empty();
 }