cc: More consistent reasoning about display list memory usage.

cc/playback/clip_path_display_item.cc

 // Copyright 2015 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_path_display_item.h"
 
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 
 namespace cc {
 
 ClipPathDisplayItem::ClipPathDisplayItem() {
 }
 
 ClipPathDisplayItem::~ClipPathDisplayItem() {
 }
 
 void ClipPathDisplayItem::SetNew(const SkPath& clip_path,
                                  SkRegion::Op clip_op,
                                  bool antialias) {
   clip_path_ = clip_path;
   clip_op_ = clip_op;
   antialias_ = antialias;
 
-  size_t memory_usage = sizeof(SkPath) + sizeof(SkRegion::Op) + sizeof(bool);
+  // The size of SkPath's external storage is not currently accounted for (and
+  // may well be shared anyway).
   DisplayItem::SetNew(true /* suitable_for_gpu_raster */, 1 /* op_count */,
-                      memory_usage);
+                      0 /* external_memory_usage */);
 }
 
 void ClipPathDisplayItem::Raster(SkCanvas* canvas,
                                  const gfx::Rect& canvas_target_playback_rect,
                                  SkPicture::AbortCallback* callback) const {
   canvas->save();
   canvas->clipPath(clip_path_, clip_op_, antialias_);
 }
 
 void ClipPathDisplayItem::AsValueInto(
     base::trace_event::TracedValue* array) const {
   array->AppendString(base::StringPrintf("ClipPathDisplayItem length: %d",
                                          clip_path_.countPoints()));
 }
 
 EndClipPathDisplayItem::EndClipPathDisplayItem() {
   DisplayItem::SetNew(true /* suitable_for_gpu_raster */, 0 /* op_count */,
-                      0 /* memory_usage */);
+                      0 /* external_memory_usage */);
 }
 
 EndClipPathDisplayItem::~EndClipPathDisplayItem() {
 }
 
 void EndClipPathDisplayItem::Raster(
     SkCanvas* canvas,
     const gfx::Rect& canvas_target_playback_rect,
     SkPicture::AbortCallback* callback) const {
   canvas->restore();
 }
 
 void EndClipPathDisplayItem::AsValueInto(
     base::trace_event::TracedValue* array) const {
   array->AppendString("EndClipPathDisplayItem");
 }
 
 }  // namespace cc