cc: Avoid expensive RenderingStats collection.

cc/picture_pile.cc

 // Copyright 2012 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 <algorithm>
 
 #include "cc/picture_pile.h"
 #include "cc/picture_pile_impl.h"
 #include "cc/region.h"
 
@@ skipping 15 matching lines @@
 PicturePile::PicturePile() {
 }
 
 PicturePile::~PicturePile() {
 }
 
 void PicturePile::Update(
     ContentLayerClient* painter,
     const Region& invalidation,
     gfx::Rect visible_layer_rect,
-    RenderingStats& stats) {
+    RenderingStats* stats) {
   gfx::Rect interest_rect = visible_layer_rect;
   interest_rect.Inset(
       -kPixelDistanceToRecord,
       -kPixelDistanceToRecord,
       -kPixelDistanceToRecord,
       -kPixelDistanceToRecord);
   for (Region::Iterator i(invalidation); i.has_rect(); i.next()) {
     // Inflate all recordings from invalidations with a margin so that when
     // scaled down to at least min_contents_scale, any final pixel touched by an
     // invalidation can be fully rasterized by this picture.
@@ skipping 98 matching lines @@
 
 
 void PicturePile::PushPropertiesTo(PicturePileImpl* other) {
   // TODO(enne): Don't clear clones or push anything if nothing has changed
   // on this layer this frame.
   PicturePileBase::PushPropertiesTo(other);
   other->clones_.clear();
 }
 
 }  // namespace cc