Add GpuMemoryBuffer support for DXGI handles.

ui/gfx/mojo/buffer_types.mojom

 // Copyright 2016 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.
 
 module gfx.mojom;
 
 // gfx::BufferFormat
 enum BufferFormat {
   ATC,
   ATCIA,
@@ skipping 26 matching lines @@
 
   LAST = GPU_READ_CPU_READ_WRITE_PERSISTENT
 };
 
 // gfx::GpuMemoryBufferType
 enum GpuMemoryBufferType {
   EMPTY_BUFFER,
   SHARED_MEMORY_BUFFER,
   IO_SURFACE_BUFFER,
   NATIVE_PIXMAP,
-  LAST = NATIVE_PIXMAP
+  DXGI_HANDLE,

[dcheng, 2017/07/12 08:46:19]

Do you mind adding a TODO to make these Windows only? It can point to
https://crbug.com/676224.

+  LAST = DXGI_HANDLE
 };
 
 // gfx::GpuMemoryBufferId
 struct GpuMemoryBufferId {
   int32 id;
 };
 
 // gfx::NativePixmapPlane
 struct NativePixmapPlane {
   uint32 stride;
@@ skipping 12 matching lines @@
 
 // gfx::GpuMemoryBufferHandle
 struct GpuMemoryBufferHandle {
   GpuMemoryBufferType type;
   GpuMemoryBufferId id;
   handle<shared_buffer>? shared_memory_handle;
   uint32 offset;
   uint32 stride;
   NativePixmapHandle? native_pixmap_handle;
   handle? mach_port;
+  handle? win32_handle;
+  uint32 array_level;
 };