Aura: Have ui::Layer implement WebKit::WebExternalTextureLayerClient

ui/compositor/compositor.h

 // Copyright (c) 2012 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_COMPOSITOR_COMPOSITOR_H_
 #define UI_COMPOSITOR_COMPOSITOR_H_
 #pragma once
 
+#include <vector>
+
+#include "base/callback.h"
 #include "base/hash_tables.h"
 #include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebLayer.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebLayerTreeView.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebLayerTreeViewClient.h"
 #include "ui/compositor/compositor_export.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/size.h"
 #include "ui/gfx/transform.h"
@@ skipping 184 matching lines @@
   // Signals swap has aborted (e.g. lost context).
   void OnSwapBuffersAborted();
 
   // WebLayerTreeViewClient implementation.
   virtual void updateAnimations(double frameBeginTime);
   virtual void layout();
   virtual void applyScrollAndScale(const WebKit::WebSize& scrollDelta,
                                    float scaleFactor);
   virtual WebKit::WebGraphicsContext3D* createContext3D();
   virtual void didRebindGraphicsContext(bool success);
+  virtual void didCommit();
   virtual void didCommitAndDrawFrame();
   virtual void didCompleteSwapBuffers();
   virtual void scheduleComposite();
 
   int last_started_frame() { return last_started_frame_; }
   int last_ended_frame() { return last_ended_frame_; }
 
+  void AddDidCommitCallback(

[piman, 2012/07/09 22:40:01]

It would be good to have the name and/or comments indicate that in the
single-threaded case, this would run the callback immediately (in a re-entrant
way). It can be unexpected to the user

[jonathan.backer, 2012/07/11 21:02:03]

You're right: it's confusing. I changed it to fire on all didCommit() signals.
If you'd like, I can add this to CompositorObserver instead (although that's
getting pretty full).

Based on our conversation, I dug deeper. In the single-threaded case,
didCommit() is signaled halfway through a draw cycle. Whereas in the threaded
case, didCommit() happens quickly after a setNeedsCommit() and can occur many
times before a draw cycle.

[piman, 2012/07/12 00:18:09]

I'd rather be consistent.
Ok, thanks.

+      const base::Callback<void(ui::Compositor*)>& callback);
+
  private:
   friend class base::RefCounted<Compositor>;
 
   // When reading back pixel data we often get RGBA rather than BGRA pixels and
   // and the image often needs to be flipped vertically.
   static void SwizzleRGBAToBGRAAndFlip(unsigned char* pixels,
                                        const gfx::Size& image_size);
 
   // Notifies the compositor that compositing is complete.
   void NotifyEnd();
@@ skipping 15 matching lines @@
   bool swap_posted_;
 
   // The device scale factor of the monitor that this compositor is compositing
   // layers on.
   float device_scale_factor_;
 
   int last_started_frame_;
   int last_ended_frame_;
 
   bool disable_schedule_composite_;
+
+  std::vector< base::Callback<void(ui::Compositor*)> >
+      did_commit_callbacks_;
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_COMPOSITOR_H_