Reland of Separate out resource mailbox creation and fix synchronization issue.

cc/resources/texture_mailbox.h

 // Copyright 2013 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_RESOURCES_TEXTURE_MAILBOX_H_
 #define CC_RESOURCES_TEXTURE_MAILBOX_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 21 matching lines @@
                  uint32_t target,
                  const gfx::Size& size_in_pixels,
                  bool is_overlay_candidate);
   TextureMailbox(SharedBitmap* shared_bitmap, const gfx::Size& size_in_pixels);
 
   ~TextureMailbox();
 
   bool IsValid() const { return IsTexture() || IsSharedMemory(); }
   bool IsTexture() const { return !mailbox_holder_.mailbox.IsZero(); }
   bool IsSharedMemory() const { return shared_bitmap_ != NULL; }
+  bool HasSyncToken() const { return mailbox_holder_.sync_token.HasData(); }
+
+  int8_t* GetSyncTokenData() { return mailbox_holder_.sync_token.GetData(); }
 
   bool Equals(const TextureMailbox&) const;
 
   const gpu::Mailbox& mailbox() const { return mailbox_holder_.mailbox; }
   const int8_t* name() const { return mailbox().name; }
   uint32_t target() const { return mailbox_holder_.texture_target; }
   const gpu::SyncToken& sync_token() const {
     return mailbox_holder_.sync_token;
   }
   void set_sync_token(const gpu::SyncToken& sync_token) {
@@ skipping 16 matching lines @@
   gpu::MailboxHolder mailbox_holder_;
   SharedBitmap* shared_bitmap_;
   gfx::Size size_in_pixels_;
   bool is_overlay_candidate_;
   bool nearest_neighbor_;
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_TEXTURE_MAILBOX_H_