Use LatencyInfoSwapPromise to track LatencyInfo through compositor

cc/trees/layer_tree_host_impl.cc

 // Copyright 2011 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 "cc/trees/layer_tree_host_impl.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/basictypes.h"
@@ skipping 453 matching lines @@
 
   LayerImpl* layer_impl =
       LayerTreeHostCommon::FindLayerThatIsHitByPointInTouchHandlerRegion(
           device_viewport_point,
           active_tree_->RenderSurfaceLayerList());
   return layer_impl != NULL;
 }
 
 void LayerTreeHostImpl::SetLatencyInfoForInputEvent(
     const ui::LatencyInfo& latency_info) {
-  active_tree()->SetLatencyInfo(latency_info);
+  scoped_ptr<cc::SwapPromise> swap_promise(

[danakj, 2013/11/26 19:17:53]

don't need cc:: inside cc::

[Yufeng Shen (Slow to review), 2013/11/27 20:05:33]

Done.

+      new cc::LatencyInfoSwapPromise(latency_info));
+  active_tree()->QueueSwapPromise(swap_promise.Pass());
 }
 
 void LayerTreeHostImpl::TrackDamageForAllSurfaces(
     LayerImpl* root_draw_layer,
     const LayerImplList& render_surface_layer_list) {
   // For now, we use damage tracking to compute a global scissor. To do this, we
   // must compute all damage tracking before drawing anything, so that we know
   // the root damage rect. The root damage rect is then used to scissor each
   // surface.
 
@@ skipping 773 matching lines @@
 }
 
 CompositorFrameMetadata LayerTreeHostImpl::MakeCompositorFrameMetadata() const {
   CompositorFrameMetadata metadata;
   metadata.device_scale_factor = device_scale_factor_;
   metadata.page_scale_factor = active_tree_->total_page_scale_factor();
   metadata.viewport_size = active_tree_->ScrollableViewportSize();
   metadata.root_layer_size = active_tree_->ScrollableSize();
   metadata.min_page_scale_factor = active_tree_->min_page_scale_factor();
   metadata.max_page_scale_factor = active_tree_->max_page_scale_factor();
-  metadata.latency_info = active_tree_->GetLatencyInfo();
+  active_tree_->TakeLatencyInfo(&metadata.latency_info);
   if (top_controls_manager_) {
     metadata.location_bar_offset =
         gfx::Vector2dF(0.f, top_controls_manager_->controls_top_offset());
     metadata.location_bar_content_translation =
         gfx::Vector2dF(0.f, top_controls_manager_->content_top_offset());
     metadata.overdraw_bottom_height = overdraw_bottom_height_;
   }
 
   if (!RootScrollLayer())
     return metadata;
@@ skipping 138 matching lines @@
 const RendererCapabilities& LayerTreeHostImpl::GetRendererCapabilities() const {
   return renderer_->Capabilities();
 }
 
 bool LayerTreeHostImpl::SwapBuffers(const LayerTreeHostImpl::FrameData& frame) {
   if (frame.has_no_damage) {
     active_tree()->BreakSwapPromises(SwapPromise::SWAP_FAILS);
     return false;
   }
   renderer_->SwapBuffers();
-  active_tree_->ClearLatencyInfo();
   active_tree()->FinishSwapPromises();
   return true;
 }
 
 void LayerTreeHostImpl::SetNeedsBeginImplFrame(bool enable) {
   if (output_surface_)
     output_surface_->SetNeedsBeginImplFrame(enable);
 }
 
 gfx::SizeF LayerTreeHostImpl::UnscaledScrollableViewportSize() const {
@@ skipping 1425 matching lines @@
   if (evicted_ui_resources_.empty())
     client_->OnCanDrawStateChanged(CanDraw());
 }
 
 void LayerTreeHostImpl::ScheduleMicroBenchmark(
     scoped_ptr<MicroBenchmarkImpl> benchmark) {
   micro_benchmark_controller_.ScheduleRun(benchmark.Pass());
 }
 
 }  // namespace cc