sync compositor: Async scroll offset IPC

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"
 #include "content/common/content_export.h"
 #include "content/common/content_param_traits.h"
 #include "content/common/input/did_overscroll_params.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"
 
 #ifndef CONTENT_COMMON_ANDROID_SYNC_COMPOSITOR_MESSAGES_H_
 #define CONTENT_COMMON_ANDROID_SYNC_COMPOSITOR_MESSAGES_H_
 
 namespace content {
 
 struct SyncCompositorCommonBrowserParams {
   SyncCompositorCommonBrowserParams();
   ~SyncCompositorCommonBrowserParams();
 
-  gfx::ScrollOffset root_scroll_offset;
-  bool update_root_scroll_offset;
   bool begin_frame_source_paused;
 };
 
 struct SyncCompositorDemandDrawHwParams {
   SyncCompositorDemandDrawHwParams();
   SyncCompositorDemandDrawHwParams(
       const gfx::Size& surface_size,
       const gfx::Transform& transform,
       const gfx::Rect& viewport,
       const gfx::Rect& clip,
@@ skipping 46 matching lines @@
 
 #endif  // CONTENT_COMMON_ANDROID_SYNC_COMPOSITOR_MESSAGES_H_
 
 // Multiply-included message file, hence no include guard.
 
 #undef IPC_MESSAGE_EXPORT
 #define IPC_MESSAGE_EXPORT CONTENT_EXPORT
 #define IPC_MESSAGE_START SyncCompositorMsgStart
 
 IPC_STRUCT_TRAITS_BEGIN(content::SyncCompositorCommonBrowserParams)
-  IPC_STRUCT_TRAITS_MEMBER(root_scroll_offset)
-  IPC_STRUCT_TRAITS_MEMBER(update_root_scroll_offset)
   IPC_STRUCT_TRAITS_MEMBER(begin_frame_source_paused)
 IPC_STRUCT_TRAITS_END()
 
 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)
@@ skipping 74 matching lines @@
                            gfx::Point /* anchor */,
                            content::SyncCompositorCommonRendererParams)
 
 IPC_MESSAGE_ROUTED1(SyncCompositorMsg_SetMemoryPolicy,
                     uint32_t /* bytes_limit */);
 
 IPC_MESSAGE_ROUTED2(SyncCompositorMsg_ReclaimResources,
                     uint32_t /* output_surface_id */,
                     cc::CompositorFrameAck);
 
+IPC_MESSAGE_ROUTED1(SyncCompositorMsg_SetScroll, gfx::ScrollOffset);
+
 // -----------------------------------------------------------------------------
 // Messages sent from the renderer to the browser.
 
 IPC_MESSAGE_ROUTED0(SyncCompositorHostMsg_OutputSurfaceCreated);
 
 IPC_MESSAGE_ROUTED1(SyncCompositorHostMsg_UpdateState,
                     content::SyncCompositorCommonRendererParams)
 
 IPC_MESSAGE_ROUTED2(SyncCompositorHostMsg_OverScroll,
                     content::SyncCompositorCommonRendererParams,
                     content::DidOverscrollParams)