Uber Comp: never change mailbox name associated with a texture object.

cc/transferable_resource.h

 // Copyright 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 CC_TRANSERABLE_RESOURCE_H_
 #define CC_TRANSERABLE_RESOURCE_H_
 
 #include <vector>
 
 #include "cc/cc_export.h"
 #include "ui/gfx/size.h"
 #include "third_party/khronos/GLES2/gl2.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebCompositorTransferableResourceList.h"
 
 namespace cc {
 
 struct Mailbox {
+  Mailbox();
+  bool isZero() const;
+  void setName(const GLbyte* name);
   GLbyte name[64];
 };
 
 struct CC_EXPORT TransferableResource {
   TransferableResource();
   ~TransferableResource();
 
   unsigned id;
   GLenum format;
   gfx::Size size;
   Mailbox mailbox;
 };
 
 typedef std::vector<TransferableResource> TransferableResourceArray;
 
 struct CC_EXPORT TransferableResourceList :
     public NON_EXPORTED_BASE(WebKit::WebCompositorTransferableResourceList) {
   TransferableResourceList();
   ~TransferableResourceList();
 
   TransferableResourceArray resources;
   unsigned sync_point;
 };
 
 }  // namespace cc
 
 #endif  // CC_TRANSERABLE_RESOURCE_H_