sync compositor: Signal async frame on IO thread

content/browser/android/synchronous_compositor_host.cc

Index: content/browser/android/synchronous_compositor_host.cc
diff --git a/content/browser/android/synchronous_compositor_host.cc b/content/browser/android/synchronous_compositor_host.cc
index 19127cf328a34587f6cf2a0583b9ec8fb16c9ea5..a510f1917086d0da7a4d92bfa5edac90f7d1e93d 100644
--- a/content/browser/android/synchronous_compositor_host.cc
+++ b/content/browser/android/synchronous_compositor_host.cc
@@ -70,7 +70,6 @@ SynchronousCompositorHost::SynchronousCompositorHost(
       ui_task_runner_(BrowserThread::GetTaskRunnerForThread(BrowserThread::UI)),
       process_id_(rwhva_->GetRenderWidgetHost()->GetProcess()->GetID()),
       routing_id_(rwhva_->GetRenderWidgetHost()->GetRoutingID()),
-      rph_observer_(SynchronousCompositorObserver::GetOrCreateFor(process_id_)),
       sender_(rwhva_->GetRenderWidgetHost()),
       use_in_process_zero_copy_software_draw_(use_in_proc_software_draw),
       bytes_limit_(0u),
@@ -91,21 +90,27 @@ bool SynchronousCompositorHost::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER(SyncCompositorHostMsg_CompositorFrameSinkCreated,
                         CompositorFrameSinkCreated)
     IPC_MESSAGE_HANDLER(SyncCompositorHostMsg_UpdateState, ProcessCommonParams)
-    IPC_MESSAGE_HANDLER_GENERIC(SyncCompositorHostMsg_ReturnFrame,
-                                DemandDrawHwReceiveFrame(message))
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
-void SynchronousCompositorHost::DemandDrawHwAsync(
+scoped_refptr<SynchronousCompositor::FrameFuture>
+SynchronousCompositorHost::DemandDrawHwAsync(
     const gfx::Size& viewport_size,
     const gfx::Rect& viewport_rect_for_tile_priority,
     const gfx::Transform& transform_for_tile_priority) {
   SyncCompositorDemandDrawHwParams params(viewport_size,
                                           viewport_rect_for_tile_priority,
                                           transform_for_tile_priority);
-  sender_->Send(new SyncCompositorMsg_DemandDrawHwAsync(routing_id_, params));
+  scoped_refptr<FrameFuture> frame_future = new FrameFuture();
+  if (SynchronousCompositorObserver* filter = GetFilter()) {
+    filter->SetFrameFuture(routing_id_, frame_future);
+    sender_->Send(new SyncCompositorMsg_DemandDrawHwAsync(routing_id_, params));
+  } else {
+    frame_future->setFrame(nullptr);
+  }
+  return frame_future;
 }
 
 SynchronousCompositor::Frame SynchronousCompositorHost::DemandDrawHw(
@@ -131,28 +136,6 @@ SynchronousCompositor::Frame SynchronousCompositorHost::DemandDrawHw(
                               std::move(compositor_frame));
 }
 
-bool SynchronousCompositorHost::DemandDrawHwReceiveFrame(
-    const IPC::Message& message) {
-  SyncCompositorHostMsg_ReturnFrame::Param param;
-  if (!SyncCompositorHostMsg_ReturnFrame::Read(&message, &param))
-    return false;
-  uint32_t compositor_frame_sink_id = std::get<0>(param);
-  cc::CompositorFrame compositor_frame = std::move(std::get<1>(param));
-  scoped_refptr<SynchronousCompositor::FrameFuture> frame_future =
-      new FrameFuture();
-  SynchronousCompositor::Frame frame = ProcessHardwareFrame(
-      compositor_frame_sink_id, std::move(compositor_frame));
-  if (!frame.frame)
-    return true;
-  std::unique_ptr<SynchronousCompositor::Frame> frame_ptr =
-      base::MakeUnique<SynchronousCompositor::Frame>();
-  frame_ptr->frame = std::move(frame.frame);
-  frame_ptr->compositor_frame_sink_id = frame.compositor_frame_sink_id;
-  frame_future->setFrame(std::move(frame_ptr));
-  client_->OnDrawHardwareProcessFrameFuture(std::move(frame_future));
-  return true;
-}
-
 SynchronousCompositor::Frame SynchronousCompositorHost::ProcessHardwareFrame(
     uint32_t compositor_frame_sink_id,
     cc::CompositorFrame compositor_frame) {
@@ -175,6 +158,12 @@ void SynchronousCompositorHost::UpdateFrameMetaData(
   rwhva_->SynchronousFrameMetadata(std::move(frame_metadata));
 }
 
+SynchronousCompositorObserver* SynchronousCompositorHost::GetFilter() {
+  return static_cast<RenderProcessHostImpl*>(
+             rwhva_->GetRenderWidgetHost()->GetProcess())
+      ->synchronous_compositor_filter();
+}
+
 namespace {
 
 class ScopedSetSkCanvas {
@@ -387,7 +376,8 @@ void SynchronousCompositorHost::DidOverscroll(
 
 void SynchronousCompositorHost::DidSendBeginFrame(
     ui::WindowAndroid* window_android) {
-  rph_observer_->SyncStateAfterVSync(window_android, this);
+  if (SynchronousCompositorObserver* filter = GetFilter())
+    filter->SyncStateAfterVSync(window_android, this);
 }
 
 void SynchronousCompositorHost::CompositorFrameSinkCreated() {