[DRAFT] Animations: Profile hash look-ups for external mutators

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 <map>
 #include <set>
@@ skipping 1714 matching lines @@
         "SwapBuffers");
     // Only add the latency component once for renderer swap, not the browser
     // swap.
     if (!latency.FindLatency(ui::INPUT_EVENT_LATENCY_RENDERER_SWAP_COMPONENT,
                              0, nullptr)) {
       latency.AddLatencyNumber(ui::INPUT_EVENT_LATENCY_RENDERER_SWAP_COMPONENT,
                                0, 0);
     }
   }
   renderer_->SwapBuffers(metadata);
+  if (animation_host_)
+    animation_host_->ReportAndClearStatsOnFrameEnd();
   return true;
 }
 
 void LayerTreeHostImpl::WillBeginImplFrame(const BeginFrameArgs& args) {
   current_begin_frame_tracker_.Start(args);
 
   if (is_likely_to_require_a_draw_) {
     // Optimistically schedule a draw. This will let us expect the tile manager
     // to complete its work so that we can draw new tiles within the impl frame
     // we are beginning now.
@@ skipping 1371 matching lines @@
   SetNeedsAnimate();
 }
 
 void LayerTreeHostImpl::AnimateLayers(base::TimeTicks monotonic_time) {
   if (!settings_.accelerated_animation_enabled || !active_tree_->root_layer())
     return;
 
   if (animation_host_) {
     if (animation_host_->AnimateLayers(monotonic_time))
       SetNeedsAnimate();
+    ReportAndClearStatsAfterAnimateLayers();
   } else {
     if (animation_registrar_->AnimateLayers(monotonic_time))
       SetNeedsAnimate();
   }
 }
 
 void LayerTreeHostImpl::UpdateAnimationState(bool start_ready_animations) {
   if (!settings_.accelerated_animation_enabled || !active_tree_->root_layer())
     return;
 
@@ skipping 474 matching lines @@
     int layer_id) const {
   if (active_tree()) {
     LayerAnimationValueProvider* layer = active_tree()->LayerById(layer_id);
     if (layer)
       return layer->ScrollOffsetForAnimation();
   }
 
   return gfx::ScrollOffset();
 }
 
+void LayerTreeHostImpl::ReportAndClearStatsAfterAnimateLayers() {
+  base::TimeDelta find_layer_by_id_stats =
+      active_tree_->find_layer_by_id_stats();
+  active_tree_->ClearStatsOnFrameEnd();
+
+  if (pending_tree_) {
+    find_layer_by_id_stats += pending_tree_->find_layer_by_id_stats();
+    pending_tree_->ClearStatsOnFrameEnd();
+  }
+  if (recycle_tree_) {
+    find_layer_by_id_stats += recycle_tree_->find_layer_by_id_stats();
+    recycle_tree_->ClearStatsOnFrameEnd();
+  }
+
+  LOCAL_HISTOGRAM_CUSTOM_COUNTS("Mutators.FindLayerImplById",
+                                find_layer_by_id_stats.InMicroseconds(), 1,
+                                1000, 10);
+}
+
 }  // namespace cc