GpuService: introduce GetGpuMemoryBufferAttribs as a mojo interface

services/ui/gpu/interfaces/gpu_service.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 ui.mojom;
 
 import "gpu/ipc/common/gpu_info.mojom";
 import "gpu/ipc/common/memory_stats.mojom";
 import "gpu/ipc/common/surface_handle.mojom";
 import "gpu/ipc/common/sync_token.mojom";
@@ skipping 17 matching lines @@
                         gfx.mojom.Size size,
                         gfx.mojom.BufferFormat format,
                         gfx.mojom.BufferUsage usage,
                         int32 client_id,
                         gpu.mojom.SurfaceHandle surface_handle)
       => (gfx.mojom.GpuMemoryBufferHandle buffer_handle);
 
   DestroyGpuMemoryBuffer(gfx.mojom.GpuMemoryBufferId id,
                          int32 client_id,
                          gpu.mojom.SyncToken sync_token);
+  GetGpuMemoryBufferAttribs()
+      => (array<gfx.mojom.GpuMemoryBufferAttrib> supported_attribs);
 
   GetVideoMemoryUsageStats() => (gpu.mojom.VideoMemoryUsageStats stats);
 
   RequestCompleteGpuInfo() => (gpu.mojom.GpuInfo gpu_info);
 
   // Notify GPU that a shader was loaded from disk.
   LoadedShader(string data);
 
   // Tells GPU to release the surface because it's being destroyed.
   DestroyingVideoSurface(int32 surface_id) => ();
 
   // Tells GPU to wake up the GPU because we're about to draw.
   WakeUpGpu();
 
   // Tells GPU that host has seen a GPU switch. This can happen when the display
   // is reconfigured, for example.
   GpuSwitched();
 
   DestroyAllChannels();
 
   Crash();
   Hang();
   ThrowJavaException();
   Stop() => ();
 };