Add compositor support for the LatencyInfo.

cc/trees/layer_tree_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_impl.h"
 
 #include "base/debug/trace_event.h"
 #include "cc/animation/animation.h"
 #include "cc/animation/animation_id_provider.h"
 #include "cc/animation/keyframed_animation_curve.h"
@@ skipping 80 matching lines @@
     currently_scrolling_layer_ ? currently_scrolling_layer_->id() : 0;
   root_scroll_layer_ = NULL;
   currently_scrolling_layer_ = NULL;
 
   render_surface_layer_list_.clear();
   set_needs_update_draw_properties();
   return root_layer_.Pass();
 }
 
 void LayerTreeImpl::PushPropertiesTo(LayerTreeImpl* target_tree) {
+  target_tree->SetLatencyInfo(latency_info_);
+  latency_info_.Clear();
   target_tree->SetPageScaleFactorAndLimits(
       page_scale_factor(), min_page_scale_factor(), max_page_scale_factor());
   target_tree->SetPageScaleDelta(
       target_tree->page_scale_delta() / target_tree->sent_page_scale_delta());
   target_tree->set_sent_page_scale_delta(1);
 
   // This should match the property synchronization in
   // LayerTreeHost::finishCommitOnImplThread().
   target_tree->set_source_frame_number(source_frame_number());
   target_tree->set_background_color(background_color());
@@ skipping 566 matching lines @@
 
   gfx::Vector2dF original_viewport_size =
       gfx::RectF(root_clip->bounds()).bottom_right() -
       gfx::PointF();
   original_viewport_size.Scale(1 / page_scale_factor());
 
   root_scroll->SetFixedContainerSizeDelta(
       scrollable_viewport_size - original_viewport_size);
 }
 
+void LayerTreeImpl::SetLatencyInfo(const LatencyInfo& latency_info) {
+  latency_info_.MergeWith(latency_info);
+}
+
+const LatencyInfo& LayerTreeImpl::GetLatencyInfo() {
+  return latency_info_;
+}
+
+void LayerTreeImpl::ClearLatencyInfo() {
+  latency_info_.Clear();
+}
+
 }  // namespace cc