OnDrawHardware() implementation with async messages

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 b0e0b9dab5a7012e3af9754467aba79c169f46ee..2a9c0820f056776919d1b8748733f8b68885da28 100644
--- a/content/browser/android/synchronous_compositor_host.cc
+++ b/content/browser/android/synchronous_compositor_host.cc
@@ -70,6 +70,8 @@ SynchronousCompositorHost::SynchronousCompositorHost(
       routing_id_(rwhva_->GetRenderWidgetHost()->GetRoutingID()),
       sender_(rwhva_->GetRenderWidgetHost()),
       use_in_process_zero_copy_software_draw_(use_in_proc_software_draw),
+      //      did_receive_first_frame_synchronously_(false),
+      sync_call_count_(0u),
       bytes_limit_(0u),
       renderer_param_version_(0u),
       need_animate_scroll_(false),
@@ -88,12 +90,13 @@ bool SynchronousCompositorHost::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER(SyncCompositorHostMsg_OutputSurfaceCreated,
                         OutputSurfaceCreated)
     IPC_MESSAGE_HANDLER(SyncCompositorHostMsg_UpdateState, ProcessCommonParams)
+    IPC_MESSAGE_HANDLER(CompositorHostMsg_Frame, DemandDrawHwReceiveFrame)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
-SynchronousCompositor::Frame SynchronousCompositorHost::DemandDrawHw(
+SynchronousCompositor::Frame SynchronousCompositorHost::DemandDrawHw_Sync(
     const gfx::Size& surface_size,
     const gfx::Transform& transform,
     const gfx::Rect& viewport,
@@ -122,6 +125,66 @@ SynchronousCompositor::Frame SynchronousCompositorHost::DemandDrawHw(
   return frame;
 }
 
+SynchronousCompositor::Frame SynchronousCompositorHost::DemandDrawHw(
+    const gfx::Size& surface_size,
+    const gfx::Transform& transform,
+    const gfx::Rect& viewport,
+    const gfx::Rect& clip,
+    const gfx::Rect& viewport_rect_for_tile_priority,
+    const gfx::Transform& transform_for_tile_priority) {
+  //  if (!did_receive_first_frame_synchronously_)
+  if (sync_call_count_++ < 60) {
+    //    did_receive_first_frame_synchronously_ = true;
+    return DemandDrawHw_Sync(surface_size, transform, viewport, clip,
+                             viewport_rect_for_tile_priority,
+                             transform_for_tile_priority);
+  }
+
+  SyncCompositorDemandDrawHwParams params(surface_size, transform, viewport,
+                                          clip, viewport_rect_for_tile_priority,
+                                          transform_for_tile_priority);
+  SynchronousCompositor::Frame frame;
+  frame.frame.reset(new cc::CompositorFrame);

[boliu, 2016/07/29 00:48:21]

you are creating a CompositorFrame here that's empty, ie without
delegated_frame_data, then in BVR, you are passing this empty frame into
ChildFrame, then into frame consumer etc

I think you should either make this method return void, or just remove all that
stuff in BVR after calling DemandDrawHw

+  //  SyncCompositorCommonRendererParams common_renderer_params;
+
+  /* Send an async message instead of a synchronous one.
+   * Currently not sure what to do in the analogous case
+   * when sending sync message returns false. */
+  //  if (!sender_->Send(new SyncCompositorMsg_DemandDrawHw(
+  //          routing_id_, params, &common_renderer_params,
+  //          &frame.output_surface_id, frame.frame.get()))) {
+  //    return SynchronousCompositor::Frame();
+  //  }
+
+  sender_->Send(new CompositorMsg_DemandDrawHw(routing_id_, params));
+
+  return frame;
+}
+
+void SynchronousCompositorHost::DemandDrawHwReceiveFrame(
+    uint32_t output_surface_id,
+    const cc::CompositorFrame& compositor_frame) {
+  //  ProcessCommonParams(common_renderer_params);
+  SynchronousCompositor::Frame frame;
+  frame.frame.reset(new cc::CompositorFrame);
+  frame.output_surface_id = output_surface_id;
+  //  *frame.frame.get() =  compositor_frame;
+  //  frame = compositor_frame;
+  // frame.frame.reset(&compositor_frame);
+  *frame.frame = std::move(const_cast<cc::CompositorFrame&>(compositor_frame));
+  frame.output_surface_id = output_surface_id;
+
+  if (!frame.frame->delegated_frame_data) {
+    // This can happen if compositor did not swap in this draw.
+    frame.frame.reset();
+  }
+  if (frame.frame) {
+    UpdateFrameMetaData(frame.frame->metadata.Clone());
+  }
+  //  return frame;
+  client_->OnDrawHardwareProcessFrame(std::move(frame));
+}
+
 void SynchronousCompositorHost::UpdateFrameMetaData(
     cc::CompositorFrameMetadata frame_metadata) {
   rwhva_->SynchronousFrameMetadata(std::move(frame_metadata));