IPC-based sync compositor software draw optimization

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 "cc/output/begin_frame_args.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/compositor_frame_ack.h"
@@ skipping 32 matching lines @@
   ~SyncCompositorDemandDrawHwParams();
 
   gfx::Size surface_size;
   gfx::Transform transform;
   gfx::Rect viewport;
   gfx::Rect clip;
   gfx::Rect viewport_rect_for_tile_priority;
   gfx::Transform transform_for_tile_priority;
 };
 
+struct SyncCompositorSetSharedMemoryParams {
+  SyncCompositorSetSharedMemoryParams();
+
+  size_t buffer_size;
+  base::SharedMemoryHandle shm_handle;
+};
+
 struct SyncCompositorDemandDrawSwParams {
   SyncCompositorDemandDrawSwParams();
   ~SyncCompositorDemandDrawSwParams();
 
   gfx::Size size;
   gfx::Rect clip;
   gfx::Transform transform;
-  base::SharedMemoryHandle shm_handle;
 };
 
 struct SyncCompositorCommonRendererParams {
   SyncCompositorCommonRendererParams();
   ~SyncCompositorCommonRendererParams();
 
   unsigned int version;
   gfx::ScrollOffset total_scroll_offset;
   gfx::ScrollOffset max_scroll_offset;
   gfx::SizeF scrollable_size;
@@ skipping 25 matching lines @@
 
 IPC_STRUCT_TRAITS_BEGIN(content::SyncCompositorDemandDrawHwParams)
   IPC_STRUCT_TRAITS_MEMBER(surface_size)
   IPC_STRUCT_TRAITS_MEMBER(transform)
   IPC_STRUCT_TRAITS_MEMBER(viewport)
   IPC_STRUCT_TRAITS_MEMBER(clip)
   IPC_STRUCT_TRAITS_MEMBER(viewport_rect_for_tile_priority)
   IPC_STRUCT_TRAITS_MEMBER(transform_for_tile_priority)
 IPC_STRUCT_TRAITS_END()
 
+IPC_STRUCT_TRAITS_BEGIN(content::SyncCompositorSetSharedMemoryParams)
+  IPC_STRUCT_TRAITS_MEMBER(buffer_size)
+  IPC_STRUCT_TRAITS_MEMBER(shm_handle)
+IPC_STRUCT_TRAITS_END()
+
 IPC_STRUCT_TRAITS_BEGIN(content::SyncCompositorDemandDrawSwParams)
   IPC_STRUCT_TRAITS_MEMBER(size)
   IPC_STRUCT_TRAITS_MEMBER(clip)
   IPC_STRUCT_TRAITS_MEMBER(transform)
-  IPC_STRUCT_TRAITS_MEMBER(shm_handle)
 IPC_STRUCT_TRAITS_END()
 
 IPC_STRUCT_TRAITS_BEGIN(content::SyncCompositorCommonRendererParams)
   IPC_STRUCT_TRAITS_MEMBER(version)
   IPC_STRUCT_TRAITS_MEMBER(total_scroll_offset)
   IPC_STRUCT_TRAITS_MEMBER(max_scroll_offset)
   IPC_STRUCT_TRAITS_MEMBER(scrollable_size)
   IPC_STRUCT_TRAITS_MEMBER(page_scale_factor)
   IPC_STRUCT_TRAITS_MEMBER(min_page_scale_factor)
   IPC_STRUCT_TRAITS_MEMBER(max_page_scale_factor)
@@ skipping 20 matching lines @@
                            content::SyncCompositorCommonBrowserParams,
                            base::TimeTicks,
                            content::SyncCompositorCommonRendererParams)
 
 IPC_SYNC_MESSAGE_ROUTED2_2(SyncCompositorMsg_DemandDrawHw,
                            content::SyncCompositorCommonBrowserParams,
                            content::SyncCompositorDemandDrawHwParams,
                            content::SyncCompositorCommonRendererParams,
                            cc::CompositorFrame)
 
+IPC_SYNC_MESSAGE_ROUTED2_2(SyncCompositorMsg_SetSharedMemory,
+                           content::SyncCompositorCommonBrowserParams,
+                           content::SyncCompositorSetSharedMemoryParams,
+                           bool /* success */,
+                           content::SyncCompositorCommonRendererParams);
+
+IPC_MESSAGE_ROUTED0(SyncCompositorMsg_ZeroSharedMemory);
+
 IPC_SYNC_MESSAGE_ROUTED2_3(SyncCompositorMsg_DemandDrawSw,
                            content::SyncCompositorCommonBrowserParams,
                            content::SyncCompositorDemandDrawSwParams,
                            bool /* result */,
                            content::SyncCompositorCommonRendererParams,
                            cc::CompositorFrame)
 
 IPC_MESSAGE_ROUTED1(SyncCompositorMsg_UpdateState,
                     content::SyncCompositorCommonBrowserParams)
 
 // -----------------------------------------------------------------------------
 // Messages sent from the renderer to the browser.
 
 IPC_MESSAGE_ROUTED1(SyncCompositorHostMsg_UpdateState,
                     content::SyncCompositorCommonRendererParams)
 
 IPC_MESSAGE_ROUTED2(SyncCompositorHostMsg_OverScroll,
                     content::SyncCompositorCommonRendererParams,
                     content::DidOverscrollParams)