cc: Move DisplayItem::Raster up to DisplayItemList

ui/compositor/paint_cache.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 "ui/compositor/paint_cache.h"
 
 #include "cc/playback/display_item_list.h"
 #include "ui/compositor/paint_context.h"
 
 namespace ui {
 
-PaintCache::PaintCache() : has_cache_(false) {
-}
+PaintCache::PaintCache() {}
 
 PaintCache::~PaintCache() {
 }
 
 bool PaintCache::UseCache(const PaintContext& context,
                           const gfx::Size& size_in_context) {
-  if (!has_cache_)
+  if (!display_item_.has_value())
     return false;
   DCHECK(context.list_);
   gfx::Rect bounds_in_layer = context.ToLayerSpaceBounds(size_in_context);
   context.list_->CreateAndAppendDrawingItem<cc::DrawingDisplayItem>(
-      bounds_in_layer, display_item_);
+      bounds_in_layer, *display_item_);
   return true;
 }
 
 void PaintCache::SetCache(const cc::DrawingDisplayItem& item) {
-  item.CloneTo(&display_item_);
-  has_cache_ = true;
+  display_item_.emplace(item);
 }
 
 }  // namespace ui