Use gpu::Mailbox instead of std:string in IPCs

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_
 
 #include <string>
 
 #include "base/containers/hash_tables.h"
@@ skipping 22 matching lines @@
 class Layer;
 class LayerTreeDebugState;
 class LayerTreeHost;
 }
 
 namespace gfx {
 class Rect;
 class Size;
 }
 
+namespace gpu {
+struct Mailbox;
+}
+
 namespace ui {
 
 class Compositor;
 class CompositorVSyncManager;
 class Layer;
 class PostedSwapQueue;
 class Reflector;
 class Texture;
 struct LatencyInfo;
 
@@ skipping 52 matching lines @@
  public:
   Texture(bool flipped, const gfx::Size& size, float device_scale_factor);
 
   bool flipped() const { return flipped_; }
   gfx::Size size() const { return size_; }
   float device_scale_factor() const { return device_scale_factor_; }
 
   virtual unsigned int PrepareTexture() = 0;
 
   // Replaces the texture with the texture from the specified mailbox.
-  virtual void Consume(const std::string& mailbox_name,
+  virtual void Consume(const gpu::Mailbox& mailbox,
                        const gfx::Size& new_size) {}
 
   // Moves the texture into the mailbox and returns the mailbox name.
   // The texture must have been previously consumed from a mailbox.
-  virtual std::string Produce();
+  virtual gpu::Mailbox Produce();
 
  protected:
   virtual ~Texture();
   gfx::Size size_;  // in pixel
 
  private:
   friend class base::RefCounted<Texture>;
 
   bool flipped_;
   float device_scale_factor_;
@@ skipping 198 matching lines @@
   bool draw_on_compositing_end_;
 
   base::WeakPtrFactory<Compositor> schedule_draw_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Compositor);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_COMPOSITOR_H_