cc: Implement unified BeginFrame on aura

ui/base/compositor/compositor_begin_frame_observer.h

Index: ui/base/compositor/compositor_begin_frame_observer.h
diff --git a/ui/base/compositor/compositor_begin_frame_observer.h b/ui/base/compositor/compositor_begin_frame_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..1e86bf76a9c5b2c47336a1480e719583db3d50df
--- /dev/null
+++ b/ui/base/compositor/compositor_begin_frame_observer.h
@@ -0,0 +1,23 @@
+// Copyright 2014 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.
+
+#ifndef UI_BASE_COMPOSITOR_COMPOSITOR_BEGIN_FRAME_OBSERVER_H_
+#define UI_BASE_COMPOSITOR_COMPOSITOR_BEGIN_FRAME_OBSERVER_H_
+
+namespace cc {
+struct BeginFrameArgs;
+}
+
+namespace ui {
+
+class CompositorBeginFrameObserver {

[brianderson, 2014/12/09 03:00:31]

Do we need this now that we have cc::BeginFrameObserver?

[simonhong, 2014/12/09 17:09:27]

IMO, both are doing different role and living in different layer although they
have a similar interface.
This is for *sending" BeginFrame where as cc::BeginFrameObserver::OnBeginFrame
is for starting
new BeginFrame.

+ public:
+  virtual ~CompositorBeginFrameObserver() {}
+
+  virtual void OnSendBeginFrame(const cc::BeginFrameArgs& args) = 0;
+};
+
+}  // namespace ui
+
+ #endif  // UI_BASE_COMPOSITOR_COMPOSITOR_BEGIN_FRAME_OBSERVER_H_