cc: More consistent reasoning about display list memory usage.

cc/playback/clip_display_item.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/clip_display_item.h"
 
 #include <string>
 
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "ui/gfx/skia_util.h"
 
 namespace cc {
 
 ClipDisplayItem::ClipDisplayItem() {
 }
 
 ClipDisplayItem::~ClipDisplayItem() {
 }
 
 void ClipDisplayItem::SetNew(gfx::Rect clip_rect,
                              const std::vector<SkRRect>& rounded_clip_rects) {
   clip_rect_ = clip_rect;
   rounded_clip_rects_ = rounded_clip_rects;
 
-  size_t memory_usage = sizeof(gfx::Rect);
-  for (size_t i = 0; i < rounded_clip_rects_.size(); ++i) {
-    memory_usage += sizeof(rounded_clip_rects_[i]);
-  }
+  size_t external_memory_usage =
+      rounded_clip_rects_.capacity() * sizeof(rounded_clip_rects_[0]);
+
   DisplayItem::SetNew(true /* suitable_for_gpu_raster */, 1 /* op_count */,
-                      memory_usage);
+                      external_memory_usage);
 }
 
 void ClipDisplayItem::Raster(SkCanvas* canvas,
                              const gfx::Rect& canvas_target_playback_rect,
                              SkPicture::AbortCallback* callback) const {
   canvas->save();
   canvas->clipRect(SkRect::MakeXYWH(clip_rect_.x(), clip_rect_.y(),
                                     clip_rect_.width(), clip_rect_.height()));
   for (size_t i = 0; i < rounded_clip_rects_.size(); ++i) {
     if (rounded_clip_rects_[i].isRect()) {
@@ skipping 27 matching lines @@
                         lower_right_radius.y());
     SkVector lower_left_radius = rounded_rect.radii(SkRRect::kLowerLeft_Corner);
     base::StringAppendF(&value, " [%f,%f]]", lower_left_radius.x(),
                         lower_left_radius.y());
   }
   array->AppendString(value);
 }
 
 EndClipDisplayItem::EndClipDisplayItem() {
   DisplayItem::SetNew(true /* suitable_for_gpu_raster */, 0 /* op_count */,
-                      0 /* memory_usage */);
+                      0 /* external_memory_usage */);
 }
 
 EndClipDisplayItem::~EndClipDisplayItem() {
 }
 
 void EndClipDisplayItem::Raster(SkCanvas* canvas,
                                 const gfx::Rect& canvas_target_playback_rect,
                                 SkPicture::AbortCallback* callback) const {
   canvas->restore();
 }
 
 void EndClipDisplayItem::AsValueInto(
     base::trace_event::TracedValue* array) const {
   array->AppendString("EndClipDisplayItem");
 }
 
 }  // namespace cc