cc: Make separate interface for BeginFrame ipc from OutputSurface

content/renderer/gpu/render_widget_compositor.cc

 // Copyright (c) 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/renderer/gpu/render_widget_compositor.h"
 
 #include <limits>
 #include <string>
 
 #include "base/command_line.h"
@@ skipping 15 matching lines @@
 #include "cc/output/begin_frame_args.h"
 #include "cc/output/copy_output_request.h"
 #include "cc/output/copy_output_result.h"
 #include "cc/resources/single_release_callback.h"
 #include "cc/trees/layer_tree_host.h"
 #include "content/child/child_gpu_memory_buffer_manager.h"
 #include "content/child/child_shared_bitmap_manager.h"
 #include "content/common/content_switches_internal.h"
 #include "content/common/gpu/client/context_provider_command_buffer.h"
 #include "content/public/common/content_switches.h"
+#include "content/renderer/gpu/compositor_external_begin_frame_source.h"
 #include "content/renderer/input/input_handler_manager.h"
 #include "content/renderer/render_thread_impl.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "third_party/WebKit/public/platform/WebCompositeAndReadbackAsyncCallback.h"
 #include "third_party/WebKit/public/platform/WebSelectionBound.h"
 #include "third_party/WebKit/public/platform/WebSize.h"
 #include "third_party/WebKit/public/web/WebKit.h"
 #include "third_party/WebKit/public/web/WebWidget.h"
 #include "ui/gfx/frame_time.h"
 #include "ui/gl/gl_switches.h"
@@ skipping 485 matching lines @@
   cc::GpuMemoryBufferManager* gpu_memory_buffer_manager = NULL;
   // render_thread may be NULL in tests.
   if (render_thread) {
     compositor_message_loop_proxy =
         render_thread->compositor_message_loop_proxy();
     shared_bitmap_manager = render_thread->shared_bitmap_manager();
     gpu_memory_buffer_manager = render_thread->gpu_memory_buffer_manager();
     main_thread_compositor_task_runner =
         render_thread->main_thread_compositor_task_runner();
   }
+  scoped_refptr<CompositorExternalBeginFrameSource> external_begin_frame_source;
+  if (settings.begin_frame_scheduling_enabled) {
+    external_begin_frame_source = new CompositorExternalBeginFrameSource(
+                                          widget_->routing_id());

[piman, 2014/10/15 03:34:50]

If both the CompositorExternalBeginFrameSource and the CompositorOutputSurface
have the same routing_id, they will stomp on each other (ForwardingMessageFilter
expects a single handler per routing id). Either you need to have a single
handler and have both the CompositorExternalBeginFrameSource and the
CompositorOutputSurface register to it, or change ForwardingMessageFilter to use
a multimap instead of a map.

[simonhong, 2014/10/15 06:45:14]

Many thanks for this.
I didn't know about it.
I modified ForwardingMessagerFilter to use a multimap.

+  }
   if (compositor_message_loop_proxy.get()) {
     layer_tree_host_ =
         cc::LayerTreeHost::CreateThreaded(this,
                                           shared_bitmap_manager,
                                           gpu_memory_buffer_manager,
                                           settings,
                                           main_thread_compositor_task_runner,
-                                          compositor_message_loop_proxy);
+                                          compositor_message_loop_proxy,
+                                          external_begin_frame_source);
   } else {
     layer_tree_host_ = cc::LayerTreeHost::CreateSingleThreaded(
         this,
         this,
         shared_bitmap_manager,
         gpu_memory_buffer_manager,
         settings,
-        main_thread_compositor_task_runner);
+        main_thread_compositor_task_runner,
+        external_begin_frame_source);
   }
   DCHECK(layer_tree_host_);
 }
 
 void RenderWidgetCompositor::setSurfaceReady() {
   // In tests without a RenderThreadImpl, don't set ready as this kicks
   // off creating output surfaces that the test can't create.
   if (RenderThreadImpl::current())
     layer_tree_host_->SetLayerTreeHostClientReady();
 }
@@ skipping 308 matching lines @@
   widget_->OnSwapBuffersAborted();
 }
 
 void RenderWidgetCompositor::RateLimitSharedMainThreadContext() {
   cc::ContextProvider* provider =
       RenderThreadImpl::current()->SharedMainThreadContextProvider().get();
   provider->ContextGL()->RateLimitOffscreenContextCHROMIUM();
 }
 
 }  // namespace content