Add initial GpuMemoryBufferSurfaceTexture implementation.

ui/gfx/gpu_memory_buffer.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 UI_GFX_GPU_MEMORY_BUFFER_H_
 #define UI_GFX_GPU_MEMORY_BUFFER_H_
 
 #include "base/memory/shared_memory.h"
 #include "build/build_config.h"
 #include "ui/gfx/gfx_export.h"
 
 #if defined(OS_ANDROID)
 #include <third_party/khronos/EGL/egl.h>
 #endif
 
 namespace gfx {
 
 enum GpuMemoryBufferType {
   EMPTY_BUFFER,
   SHARED_MEMORY_BUFFER,
   EGL_CLIENT_BUFFER,
   IO_SURFACE_BUFFER,
-  GPU_MEMORY_BUFFER_TYPE_LAST = IO_SURFACE_BUFFER
+  SURFACE_TEXTURE_BUFFER,
+  GPU_MEMORY_BUFFER_TYPE_LAST = SURFACE_TEXTURE_BUFFER
 };
 
 struct GpuMemoryBufferHandle {
   GpuMemoryBufferHandle()
       : type(EMPTY_BUFFER),
         handle(base::SharedMemory::NULLHandle())
 #if defined(OS_ANDROID)
         , native_buffer(NULL)
 #endif
 #if defined(OS_MACOSX)
         , io_surface_id(0)
 #endif
+#if defined(OS_ANDROID)
+        , surface_texture_id(0)
+#endif
   {
   }
   bool is_null() const { return type == EMPTY_BUFFER; }
   GpuMemoryBufferType type;
   base::SharedMemoryHandle handle;
 #if defined(OS_ANDROID)
   EGLClientBuffer native_buffer;
 #endif
 #if defined(OS_MACOSX)
   uint32 io_surface_id;
 #endif
-
+#if defined(OS_ANDROID)
+  uint32 surface_texture_id;

[epennerAtGoogle, 2014/03/12 00:45:06]

Throughout this patch, I'd like it if we can make it very clear that these ID's
come from a certain 'name-space' of SurfaceTextures. They will have more and
more uses of SurfaceTexture, and not all of them have an ID from this source of
IDs and you can't find the source of 'int' as easily in code-search. Possibly
longer names like name_space_surface_texture_id, or even a real type with
::GetID(), might help?

[reveman, 2014/03/12 16:07:06]

Would a simple typedef int SurfaceTextureID help?

[epennerAtGoogle, 2014/03/12 19:46:28]

Yeppers!

[reveman, 2014/03/13 21:36:00]

I started doing this but realized I need to put it in a separate file to do it
properly. ui/gfx/android/surface_texture_id.h or something like that. Not sure
that's worth it. At least I made it consistently "int" in latest patch but I
don't think that addresses your concern. I think "int" is fine but I'll go ahead
and add a new file for this if you feel strongly about it. Let me know.

+#endif
 };
 
 // Interface for creating and accessing a zero-copy GPU memory buffer.
 // This design evolved from the generalization of GraphicBuffer API
 // of Android framework.
 //
 // THREADING CONSIDERATIONS:
 //
 // This interface is thread-safe. However, multiple threads mapping
 // a buffer for Write or ReadOrWrite simultaneously may result in undefined
@@ skipping 24 matching lines @@
   // Returns the stride in bytes for the buffer.
   virtual uint32 GetStride() const = 0;
 
   // Returns a platform specific handle for this buffer.
   virtual GpuMemoryBufferHandle GetHandle() const = 0;
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_GPU_MEMORY_BUFFER_H_