Add fixed raster scale use counter histograms.

cc/layers/layer_impl.cc

Index: cc/layers/layer_impl.cc
diff --git a/cc/layers/layer_impl.cc b/cc/layers/layer_impl.cc
index e5ea46ffb0247ebe0bbcf1b0ce747138a934782f..d59bb079f73a225de62ee345b458c31739b9882e 100644
--- a/cc/layers/layer_impl.cc
+++ b/cc/layers/layer_impl.cc
@@ -83,7 +83,8 @@ LayerImpl::LayerImpl(LayerTreeImpl* tree_impl, int id)
       mutable_properties_(MutableProperty::kNone),
       debug_info_(nullptr),
       scrolls_drawn_descendant_(false),
-      layer_or_descendant_has_touch_handler_(false) {
+      layer_or_descendant_has_touch_handler_(false),
+      has_will_change_transform_hint_(false) {
   DCHECK_GT(layer_id_, 0);
 
   DCHECK(layer_tree_impl_);
@@ -146,6 +147,13 @@ void LayerImpl::ClearLinksToOtherLayers() {
   replica_layer_ = nullptr;
 }
 
+void LayerImpl::SetHasWillChangeTransformHint(bool has_will_change) {
+  if (has_will_change_transform_hint_ == has_will_change)
+    return;
+  has_will_change_transform_hint_ = has_will_change;
+  SetNeedsPushProperties();
+}
+
 void LayerImpl::SetDebugInfo(
     std::unique_ptr<base::trace_event::ConvertableToTraceFormat> debug_info) {
   owned_debug_info_ = std::move(debug_info);
@@ -493,6 +501,8 @@ void LayerImpl::PushPropertiesTo(LayerImpl* layer) {
   if (owned_debug_info_)
     layer->SetDebugInfo(std::move(owned_debug_info_));
 
+  layer->SetHasWillChangeTransformHint(has_will_change_transform_hint());

[danakj, 2016/05/10 22:05:30]

move this up with other simple setters. line 477?

[vmpstr, 2016/05/13 00:13:34]

Done.

+
   // Reset any state that should be cleared for the next update.
   layer_property_changed_ = false;
   update_rect_ = gfx::Rect();
@@ -1252,6 +1262,9 @@ void LayerImpl::AsValueInto(base::trace_event::TracedValue* state) const {
   state->SetBoolean("has_animation_bounds",
                     layer_tree_impl_->HasAnimationThatInflatesBounds(this));
 
+  state->SetBoolean("has_will_change_transform_hint",
+                    has_will_change_transform_hint());
+
   gfx::BoxF box;
   if (LayerUtils::GetAnimationBounds(*this, &box))
     MathUtil::AddToTracedValue("animation_bounds", box, state);