cc: More consistent reasoning about display list memory usage.

cc/playback/compositing_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/compositing_display_item.h"
 
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkPaint.h"
@@ skipping 13 matching lines @@
                                     SkRect* bounds,
                                     skia::RefPtr<SkColorFilter> cf) {
   alpha_ = alpha;
   xfermode_ = xfermode;
   has_bounds_ = !!bounds;
   if (bounds)
     bounds_ = SkRect(*bounds);
   color_filter_ = cf;
 
   // TODO(pdr): Include color_filter's memory here.
-  size_t memory_usage =
-      sizeof(float) + sizeof(bool) + sizeof(SkRect) + sizeof(SkXfermode::Mode);
+  size_t external_memory_usage = 0;
   DisplayItem::SetNew(true /* suitable_for_gpu_raster */, 1 /* op_count */,
-                      memory_usage);
+                      external_memory_usage);
 }
 
 void CompositingDisplayItem::Raster(
     SkCanvas* canvas,
     const gfx::Rect& canvas_target_playback_rect,
     SkPicture::AbortCallback* callback) const {
   SkPaint paint;
   paint.setXfermodeMode(xfermode_);
   paint.setAlpha(alpha_);
   paint.setColorFilter(color_filter_.get());
   canvas->saveLayer(has_bounds_ ? &bounds_ : nullptr, &paint);
 }
 
 void CompositingDisplayItem::AsValueInto(
     base::trace_event::TracedValue* array) const {
   array->AppendString(base::StringPrintf(
       "CompositingDisplayItem alpha: %d, xfermode: %d", alpha_, xfermode_));
   if (has_bounds_)
     array->AppendString(base::StringPrintf(
         ", bounds: [%f, %f, %f, %f]", static_cast<float>(bounds_.x()),
         static_cast<float>(bounds_.y()), static_cast<float>(bounds_.width()),
         static_cast<float>(bounds_.height())));
 }
 
 EndCompositingDisplayItem::EndCompositingDisplayItem() {
   DisplayItem::SetNew(true /* suitable_for_gpu_raster */, 0 /* op_count */,
-                      0 /* memory_usage */);
+                      0 /* external_memory_usage */);
 }
 
 EndCompositingDisplayItem::~EndCompositingDisplayItem() {
 }
 
 void EndCompositingDisplayItem::Raster(
     SkCanvas* canvas,
     const gfx::Rect& canvas_target_playback_rect,
     SkPicture::AbortCallback* callback) const {
   canvas->restore();
 }
 
 void EndCompositingDisplayItem::AsValueInto(
     base::trace_event::TracedValue* array) const {
   array->AppendString("EndCompositingDisplayItem");
 }
 
 }  // namespace cc