Refactor MutatorHostClient from LayerTreeHost to LayerTree.

cc/debug/invalidation_benchmark.cc

 // Copyright 2014 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/debug/invalidation_benchmark.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 #include <limits>
@@ skipping 45 matching lines @@
     mode_ = VIEWPORT;
   } else {
     CHECK(false) << "Invalid mode: " << mode_string
                  << ". One of {fixed_size, layer, viewport, random} expected.";
   }
 }
 
 InvalidationBenchmark::~InvalidationBenchmark() {
 }
 
 void InvalidationBenchmark::DidUpdateLayers(LayerTreeHost* host) {

[Khushal, 2016/08/15 17:46:39]

How about updating the MicroBenchmark interface to take a LayerTree itself here?

[xingliu, 2016/08/15 21:29:12]

I think it makes sense, and there isn't too much work for this refactoring, but
maybe we can do it in a separate CL? since it's like modify an interface in
cc/debug.

   LayerTreeHostCommon::CallFunctionForEveryLayer(
-      host, [this](Layer* layer) { layer->RunMicroBenchmark(this); });
+      host->GetLayerTree(),
+      [this](Layer* layer) { layer->RunMicroBenchmark(this); });
 }
 
 void InvalidationBenchmark::RunOnLayer(PictureLayer* layer) {
   PropertyTrees* property_trees = layer->layer_tree_host()->property_trees();
   LayerList update_list;
   update_list.push_back(layer);
   draw_property_utils::ComputeVisibleRectsForTesting(
       property_trees, property_trees->non_root_surfaces_enabled, &update_list);
   gfx::Rect visible_layer_rect = layer->visible_layer_rect_for_testing();
   switch (mode_) {
@@ skipping 52 matching lines @@
 // high quality, but they need to be identical in each run. Therefore, we use a
 // LCG and keep the state locally in the benchmark.
 float InvalidationBenchmark::LCGRandom() {
   const uint32_t a = 1664525;
   const uint32_t c = 1013904223;
   seed_ = a * seed_ + c;
   return static_cast<float>(seed_) / std::numeric_limits<uint32_t>::max();
 }
 
 }  // namespace cc