Update from https://crrev.com/304121

cc/debug/rendering_stats.cc

Index: cc/debug/rendering_stats.cc
diff --git a/cc/debug/rendering_stats.cc b/cc/debug/rendering_stats.cc
index 558c882ec7c8f4a93f6227af9b9e4f509a815450..9c62a3c5ea6600683b5e5fdde71bea7246f8eeef 100644
--- a/cc/debug/rendering_stats.cc
+++ b/cc/debug/rendering_stats.cc
@@ -18,9 +18,8 @@ void RenderingStats::TimeDeltaList::Append(base::TimeDelta value) {
 
 void RenderingStats::TimeDeltaList::AddToTracedValue(
     base::debug::TracedValue* list_value) const {
-  std::list<base::TimeDelta>::const_iterator iter;
-  for (iter = values.begin(); iter != values.end(); ++iter) {
-    list_value->AppendDouble(iter->InMillisecondsF());
+  for (const auto& value : values) {
+    list_value->AppendDouble(value.InMillisecondsF());
   }
 }
 
@@ -32,43 +31,17 @@ base::TimeDelta RenderingStats::TimeDeltaList::GetLastTimeDelta() const {
   return values.empty() ? base::TimeDelta() : values.back();
 }
 
-RenderingStats::MainThreadRenderingStats::MainThreadRenderingStats()
-    : painted_pixel_count(0), recorded_pixel_count(0) {
-}
-
-RenderingStats::MainThreadRenderingStats::~MainThreadRenderingStats() {
-}
-
-scoped_refptr<base::debug::ConvertableToTraceFormat>
-RenderingStats::MainThreadRenderingStats::AsTraceableData() const {
-  scoped_refptr<base::debug::TracedValue> record_data =
-      new base::debug::TracedValue();
-  record_data->SetDouble("paint_time", paint_time.InSecondsF());
-  record_data->SetInteger("painted_pixel_count", painted_pixel_count);
-  record_data->SetDouble("record_time", record_time.InSecondsF());
-  record_data->SetInteger("recorded_pixel_count", recorded_pixel_count);
-  return record_data;
-}
-
-void RenderingStats::MainThreadRenderingStats::Add(
-    const MainThreadRenderingStats& other) {
-  paint_time += other.paint_time;
-  painted_pixel_count += other.painted_pixel_count;
-  record_time += other.record_time;
-  recorded_pixel_count += other.recorded_pixel_count;
-}
-
-RenderingStats::ImplThreadRenderingStats::ImplThreadRenderingStats()
+RenderingStats::RenderingStats()
     : frame_count(0),
       visible_content_area(0),
       approximated_visible_content_area(0) {
 }
 
-RenderingStats::ImplThreadRenderingStats::~ImplThreadRenderingStats() {
+RenderingStats::~RenderingStats() {
 }
 
 scoped_refptr<base::debug::ConvertableToTraceFormat>
-RenderingStats::ImplThreadRenderingStats::AsTraceableData() const {
+RenderingStats::AsTraceableData() const {
   scoped_refptr<base::debug::TracedValue> record_data =
       new base::debug::TracedValue();
   record_data->SetInteger("frame_count", frame_count);
@@ -102,8 +75,7 @@ RenderingStats::ImplThreadRenderingStats::AsTraceableData() const {
   return record_data;
 }
 
-void RenderingStats::ImplThreadRenderingStats::Add(
-    const ImplThreadRenderingStats& other) {
+void RenderingStats::Add(const RenderingStats& other) {
   frame_count += other.frame_count;
   visible_content_area += other.visible_content_area;
   approximated_visible_content_area += other.approximated_visible_content_area;
@@ -119,9 +91,4 @@ void RenderingStats::ImplThreadRenderingStats::Add(
       other.commit_to_activate_duration_estimate);
 }
 
-void RenderingStats::Add(const RenderingStats& other) {
-  main_stats.Add(other.main_stats);
-  impl_stats.Add(other.impl_stats);
-}
-
 }  // namespace cc