cc: Add GpuMemoryBufferHandle to TextureMailbox

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>
 
 #include <string>
 
 #include "base/memory/shared_memory.h"
 #include "cc/base/cc_export.h"
 #include "gpu/command_buffer/common/mailbox_holder.h"
 #include "ui/gfx/geometry/size.h"
+#include "ui/gfx/gpu_memory_buffer.h"
 
 namespace cc {
 class SharedBitmap;
 
 // TODO(skaslev, danakj) Rename this class more apropriately since now it
 // can hold a shared memory resource as well as a texture mailbox.
 class CC_EXPORT TextureMailbox {
  public:
   TextureMailbox();
   explicit TextureMailbox(const gpu::MailboxHolder& mailbox_holder);
   TextureMailbox(const gpu::Mailbox& mailbox,
                  const gpu::SyncToken& sync_token,
                  uint32_t target);
   TextureMailbox(const gpu::Mailbox& mailbox,
                  const gpu::SyncToken& sync_token,
                  uint32_t target,
                  const gfx::Size& size_in_pixels,
+                 const gfx::GpuMemoryBufferHandle& gpu_memory_buffer_handle,
                  bool is_overlay_candidate,
                  bool secure_output_only);
   TextureMailbox(SharedBitmap* shared_bitmap, const gfx::Size& size_in_pixels);
+  TextureMailbox(const TextureMailbox& other);
 
   ~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(); }
 
@@ skipping 19 matching lines @@
   // This is valid if allow_overlau() or IsSharedMemory() is true.
   gfx::Size size_in_pixels() const { return size_in_pixels_; }
 
   SharedBitmap* shared_bitmap() const { return shared_bitmap_; }
   size_t SharedMemorySizeInBytes() const;
 
  private:
   gpu::MailboxHolder mailbox_holder_;
   SharedBitmap* shared_bitmap_;
   gfx::Size size_in_pixels_;
+  gfx::GpuMemoryBufferHandle gpu_memory_buffer_handle_;

[reveman, 2016/04/29 10:05:05]

Can this be a "gfx::GpuMemoryBuffer*" and the handle is only created when this
needs to be sent over IPC? In the case of the UI compositor there might not be a
need for creating a handle.

[ccameron, 2016/04/29 17:33:32]

To me it felt much more natural to use a gfx::GpuMemoryBufferHandle here as
compared with a pointer. 

Couple of reasons:
- The cc::ResourceProvider takes ownership (via unique_ptr) of the
GpuMemoryBuffer, which would create lifetime issues for the object (both cc/ and
the caller want to own the GMB object)

- I prototyped plugging this in to the video code, and the GMB handle fit very
cleanly with
https://code.google.com/p/chromium/codesearch#chromium/src/media/base/video_f...

So to me it seems that passing via handle is better (but I do have a Mac-centric
worldview).

   bool is_overlay_candidate_;
   bool secure_output_only_;
   bool nearest_neighbor_;
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_TEXTURE_MAILBOX_H_