Restructure public side of gpu service.

mojo/services/public/interfaces/gpu/command_buffer.mojom

-// Copyright 2014 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 mojo;
-
-import "mojo/services/public/interfaces/gpu/gpu_capabilities.mojom";
-
-struct CommandBufferState {
-  int32 num_entries;
-  int32 get_offset;
-  int32 put_offset;
-  int32 token;
-  int32 error;  // TODO(piman): enum
-  int32 context_lost_reason;  // TODO(piman): enum
-  uint32 generation;
-};
-
-interface CommandBufferSyncClient {
-  DidInitialize(bool success, GpuCapabilities capabilities);
-  DidMakeProgress(CommandBufferState? state);
-};
-
-interface CommandBufferSyncPointClient {
-  DidInsertSyncPoint(uint32 sync_point);
-};
-
-[Client=CommandBufferClient]
-interface CommandBuffer {
-  Initialize(CommandBufferSyncClient? sync_client,
-             CommandBufferSyncPointClient? sync_point_client,
-             handle<shared_buffer>? shared_state);
-  SetGetBuffer(int32 buffer);
-  Flush(int32 put_offset);
-  MakeProgress(int32 last_get_offset);
-  RegisterTransferBuffer(
-      int32 id, handle<shared_buffer>? transfer_buffer, uint32 size);
-  DestroyTransferBuffer(int32 id);
-
-  // InsertSyncPoint returns the sync point returned via DidInsertSyncPoint.
-  // If |retire| is true, the sync point is retired on insertion. Otherwise,
-  // explicitly call RetireSyncPoint to retire it.
-  InsertSyncPoint(bool retire);
-  RetireSyncPoint(uint32 sync_point);
-  Echo() => ();
-
-  // TODO(piman): sync points
-};
-
-interface CommandBufferClient {
-  DidDestroy();
-  LostContext(int32 lost_reason);  // TODO(piman): enum
-};