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

cc/transferable_resource.cc

 // 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.
 
 #include "cc/transferable_resource.h"
 
 namespace cc {
 
+Mailbox::Mailbox() {
+  memset(&name, 0, sizeof(name));
+}
+
 TransferableResource::TransferableResource()
     : id(0),
       format(0) {
 }
 
 TransferableResource::~TransferableResource() {
 }
 
 TransferableResourceList::TransferableResourceList()
     : sync_point(0) {
 }
 
 TransferableResourceList::~TransferableResourceList() {
 }
 
 }  // namespace cc