cc: More consistent reasoning about display list memory usage.

cc/playback/display_list_raster_source.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/playback/display_list_raster_source.h"
 
 #include "base/trace_event/trace_event.h"
 #include "cc/base/region.h"
 #include "cc/debug/debug_colors.h"
 #include "cc/playback/display_item_list.h"
@@ skipping 120 matching lines @@
     PlaybackToCanvas(canvas, display_list_rect, display_list_rect, 1.0);
   skia::RefPtr<SkPicture> picture =
       skia::AdoptRef(recorder.endRecordingAsPicture());
 
   return picture;
 }
 
 size_t DisplayListRasterSource::GetPictureMemoryUsage() const {
   if (!display_list_)
     return 0;
-  return display_list_->PictureMemoryUsage();
+  return display_list_->ApproximateMemoryUsage();
 }
 
 void DisplayListRasterSource::PerformSolidColorAnalysis(
     const gfx::Rect& content_rect,
     float contents_scale,
     RasterSource::SolidColorAnalysis* analysis) const {
   DCHECK(analysis);
   TRACE_EVENT0("cc", "DisplayListRasterSource::PerformSolidColorAnalysis");
 
   gfx::Rect layer_rect =
@@ skipping 73 matching lines @@
 }
 
 scoped_refptr<RasterSource> DisplayListRasterSource::CreateCloneWithoutLCDText()
     const {
   bool can_use_lcd_text = false;
   return scoped_refptr<RasterSource>(
       new DisplayListRasterSource(this, can_use_lcd_text));
 }
 
 }  // namespace cc