Add fixed raster scale use counter histograms.

cc/trees/layer_tree_host.cc

Index: cc/trees/layer_tree_host.cc
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index fee2d6c61e4f92a745574b96d3008c01245076af..94173621629b9d7d88784aeb7011b92f6516a570 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -246,7 +246,9 @@ LayerTreeHost::LayerTreeHost(InitParams* params, CompositorMode mode)
       task_graph_runner_(params->task_graph_runner),
       image_serialization_processor_(params->image_serialization_processor),
       surface_id_namespace_(0u),
-      next_surface_sequence_(1u) {
+      next_surface_sequence_(1u),
+      has_fixed_raster_scale_blurry_content_(false),
+      has_fixed_raster_scale_potential_performance_regression_(false) {
   DCHECK(task_graph_runner_);
 
   animation_host_ = AnimationHost::Create(ThreadInstance::MAIN);
@@ -546,6 +548,11 @@ void LayerTreeHost::FinishCommitOnImplThread(LayerTreeHostImpl* host_impl) {
   else
     property_trees_.ResetAllChangeTracking(
         PropertyTrees::ResetFlags::TRANSFORM_TREE);
+
+  has_fixed_raster_scale_blurry_content_ =
+      host_impl->has_fixed_raster_scale_blurry_content();
+  has_fixed_raster_scale_potential_performance_regression_ =
+      host_impl->HasFixedRasterScalePotentialPerformanceRegression();
 }
 
 void LayerTreeHost::WillCommit() {
@@ -574,6 +581,9 @@ void LayerTreeHost::CommitComplete() {
     client_->DidCompletePageScaleAnimation();
     did_complete_scale_animation_ = false;
   }
+  client_->ReportFixedRasterScaleUseCounters(
+      has_fixed_raster_scale_blurry_content_,
+      has_fixed_raster_scale_potential_performance_regression_);
 }
 
 void LayerTreeHost::SetOutputSurface(std::unique_ptr<OutputSurface> surface) {