Switching to base::Optional<CompositorFrame> in Android's synchronous compositor IPC messages

content/common/android/sync_compositor_messages.h

 // Copyright 2015 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.
 
 #include <stddef.h>
 
 #include "base/memory/shared_memory_handle.h"
+#include "base/optional.h"
 #include "cc/output/begin_frame_args.h"
 #include "cc/output/compositor_frame.h"
 #include "content/common/content_export.h"
 #include "content/common/content_param_traits.h"
 #include "content/common/input/input_event_ack_state.h"
 #include "ipc/ipc_message_macros.h"
 #include "third_party/WebKit/public/web/WebInputEvent.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/scroll_offset.h"
 
@@ skipping 106 matching lines @@
 IPC_MESSAGE_ROUTED1(SyncCompositorMsg_ComputeScroll,
                     base::TimeTicks);
 
 IPC_MESSAGE_ROUTED1(SyncCompositorMsg_DemandDrawHwAsync,
                     content::SyncCompositorDemandDrawHwParams)
 
 IPC_SYNC_MESSAGE_ROUTED1_3(SyncCompositorMsg_DemandDrawHw,
                            content::SyncCompositorDemandDrawHwParams,
                            content::SyncCompositorCommonRendererParams,
                            uint32_t /* compositor_frame_sink_id */,
-                           cc::CompositorFrame)
+                           base::Optional<cc::CompositorFrame>);
 
 IPC_SYNC_MESSAGE_ROUTED1_2(SyncCompositorMsg_SetSharedMemory,
                            content::SyncCompositorSetSharedMemoryParams,
                            bool /* success */,
                            content::SyncCompositorCommonRendererParams);
 
 IPC_MESSAGE_ROUTED0(SyncCompositorMsg_ZeroSharedMemory);
 
 IPC_SYNC_MESSAGE_ROUTED1_3(SyncCompositorMsg_DemandDrawSw,
                            content::SyncCompositorDemandDrawSwParams,
@@ skipping 18 matching lines @@
 // -----------------------------------------------------------------------------
 // Messages sent from the renderer to the browser.
 
 IPC_MESSAGE_ROUTED0(SyncCompositorHostMsg_CompositorFrameSinkCreated);
 
 IPC_MESSAGE_ROUTED1(SyncCompositorHostMsg_UpdateState,
                     content::SyncCompositorCommonRendererParams)
 
 IPC_MESSAGE_ROUTED2(SyncCompositorHostMsg_ReturnFrame,
                     uint32_t /* compositor_frame_sink_id */,
-                    cc::CompositorFrame);
+                    base::Optional<cc::CompositorFrame>);