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

content/common/gpu/texture_image_transport_surface.h

Index: content/common/gpu/texture_image_transport_surface.h
diff --git a/content/common/gpu/texture_image_transport_surface.h b/content/common/gpu/texture_image_transport_surface.h
index b29a97ad92dc2af25c2a74bedb0a9f1e85f8450a..8b0e2665a6d753cddf19114400cb1af5dd185027 100644
--- a/content/common/gpu/texture_image_transport_surface.h
+++ b/content/common/gpu/texture_image_transport_surface.h
@@ -10,6 +10,7 @@
 #include "base/basictypes.h"
 #include "content/common/gpu/gpu_command_buffer_stub.h"
 #include "content/common/gpu/image_transport_surface.h"
+#include "gpu/command_buffer/common/mailbox.h"
 #include "gpu/command_buffer/service/mailbox_manager.h"
 #include "gpu/command_buffer/service/texture_manager.h"
 #include "ui/gl/gl_context.h"
@@ -71,14 +72,14 @@ class TextureImageTransportSurface
 
     // The mailbox name for the current service_id. Needs to be unique per
     // GL texture and is invalid while service_id is zero.
-    gpu::gles2::MailboxName mailbox_name;
+    gpu::Mailbox mailbox_name;
   };
 
   virtual ~TextureImageTransportSurface();
   void CreateBackTexture();
   void AttachBackTextureToFBO();
   void ReleaseBackTexture();
-  void BufferPresentedImpl(const std::string& mailbox_name);
+  void BufferPresentedImpl(const gpu::Mailbox& mailbox_name);
   void ProduceTexture(Texture* texture);
   void ConsumeTexture(Texture* texture);