cc: More consistent reasoning about display list memory usage.

cc/playback/filter_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/filter_display_item.h"
 
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "cc/output/render_surface_filters.h"
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkImageFilter.h"
 #include "third_party/skia/include/core/SkPaint.h"
 #include "third_party/skia/include/core/SkXfermode.h"
 #include "ui/gfx/skia_util.h"
 
 namespace cc {
 
 FilterDisplayItem::FilterDisplayItem() {
 }
 
 FilterDisplayItem::~FilterDisplayItem() {
 }
 
 void FilterDisplayItem::SetNew(const FilterOperations& filters,
                                const gfx::RectF& bounds) {
   filters_ = filters;
   bounds_ = bounds;
 
-  size_t memory_usage =
-      sizeof(skia::RefPtr<SkImageFilter>) + sizeof(gfx::RectF);
+  // FilterOperations doesn't expose its capacity, but size is probably good
+  // enough.
+  size_t external_memory_usage = filters_.size() * sizeof(filters_.at(0));
   DisplayItem::SetNew(true /* suitable_for_gpu_raster */, 1 /* op_count */,
-                      memory_usage);
+                      external_memory_usage);
 }
 
 void FilterDisplayItem::Raster(SkCanvas* canvas,
                                const gfx::Rect& canvas_target_playback_rect,
                                SkPicture::AbortCallback* callback) const {
   canvas->save();
   canvas->translate(bounds_.x(), bounds_.y());
 
   skia::RefPtr<SkImageFilter> image_filter =
       RenderSurfaceFilters::BuildImageFilter(
@@ skipping 11 matching lines @@
 }
 
 void FilterDisplayItem::AsValueInto(
     base::trace_event::TracedValue* array) const {
   array->AppendString(base::StringPrintf("FilterDisplayItem bounds: [%s]",
                                          bounds_.ToString().c_str()));
 }
 
 EndFilterDisplayItem::EndFilterDisplayItem() {
   DisplayItem::SetNew(true /* suitable_for_gpu_raster */, 0 /* op_count */,
-                      0 /* memory_usage */);
+                      0 /* external_memory_usage */);
 }
 
 EndFilterDisplayItem::~EndFilterDisplayItem() {
 }
 
 void EndFilterDisplayItem::Raster(SkCanvas* canvas,
                                   const gfx::Rect& canvas_target_playback_rect,
                                   SkPicture::AbortCallback* callback) const {
   canvas->restore();
   canvas->restore();
 }
 
 void EndFilterDisplayItem::AsValueInto(
     base::trace_event::TracedValue* array) const {
   array->AppendString("EndFilterDisplayItem");
 }
 
 }  // namespace cc