sync compositor: Send ipc reply in swap

content/browser/android/in_process/synchronous_compositor_impl.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/android/in_process/synchronous_compositor_impl.h"
 
+#include <utility>
+
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/lazy_instance.h"
 #include "base/message_loop/message_loop.h"
 #include "content/browser/android/in_process/synchronous_compositor_factory_impl.h"
 #include "content/browser/android/in_process/synchronous_compositor_registry_in_proc.h"
 #include "content/browser/android/in_process/synchronous_input_event_filter.h"
 #include "content/browser/gpu/gpu_process_host.h"
 #include "content/browser/renderer_host/render_widget_host_view_android.h"
 #include "content/common/input/did_overscroll_params.h"
@@ skipping 139 matching lines @@
 scoped_ptr<cc::CompositorFrame> SynchronousCompositorImpl::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) {
   DCHECK(CalledOnValidThread());
   DCHECK(output_surface_);
   DCHECK(begin_frame_source_);
+  DCHECK(!frame_holder_);
 
-  scoped_ptr<cc::CompositorFrame> frame =
-      output_surface_->DemandDrawHw(surface_size,
-                                    transform,
-                                    viewport,
-                                    clip,
-                                    viewport_rect_for_tile_priority,
-                                    transform_for_tile_priority);
+  output_surface_->DemandDrawHw(surface_size, transform, viewport, clip,
+                                viewport_rect_for_tile_priority,
+                                transform_for_tile_priority);
 
-  if (frame.get())
-    UpdateFrameMetaData(frame->metadata);
+  if (frame_holder_)
+    UpdateFrameMetaData(frame_holder_->metadata);
 
-  return frame.Pass();
+  return std::move(frame_holder_);
 }
 
 void SynchronousCompositorImpl::ReturnResources(
     const cc::CompositorFrameAck& frame_ack) {
   DCHECK(CalledOnValidThread());
   output_surface_->ReturnResources(frame_ack);
 }
 
 bool SynchronousCompositorImpl::DemandDrawSw(SkCanvas* canvas) {
   DCHECK(CalledOnValidThread());
   DCHECK(output_surface_);
   DCHECK(begin_frame_source_);
+  DCHECK(!frame_holder_);
 
-  scoped_ptr<cc::CompositorFrame> frame =
-      output_surface_->DemandDrawSw(canvas);
+  output_surface_->DemandDrawSw(canvas);
 
-  if (frame.get())
-    UpdateFrameMetaData(frame->metadata);
+  bool success = !!frame_holder_;
+  if (frame_holder_) {
+    UpdateFrameMetaData(frame_holder_->metadata);
+    frame_holder_.reset();
+  }
 
-  return !!frame.get();
+  return success;
+}
+
+void SynchronousCompositorImpl::SwapBuffers(cc::CompositorFrame* frame) {
+  DCHECK(!frame_holder_);
+  frame_holder_.reset(new cc::CompositorFrame);
+  frame->AssignTo(frame_holder_.get());
 }
 
 void SynchronousCompositorImpl::UpdateFrameMetaData(
     const cc::CompositorFrameMetadata& frame_metadata) {
   rwhva_->SynchronousFrameMetadata(frame_metadata);
   DeliverMessages();
 }
 
 void SynchronousCompositorImpl::SetMemoryPolicy(size_t bytes_limit) {
   DCHECK(CalledOnValidThread());
@@ skipping 140 matching lines @@
   }
 }
 
 // Not using base::NonThreadSafe as we want to enforce a more exacting threading
 // requirement: SynchronousCompositorImpl() must only be used on the UI thread.
 bool SynchronousCompositorImpl::CalledOnValidThread() const {
   return BrowserThread::CurrentlyOn(BrowserThread::UI);
 }
 
 }  // namespace content