cc: Add RandomAccessListContainer, which has more restricted API.

cc/playback/display_item_list.h

 // 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.
 
 #ifndef CC_PLAYBACK_DISPLAY_ITEM_LIST_H_
 #define CC_PLAYBACK_DISPLAY_ITEM_LIST_H_
 
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 82 matching lines @@
   // periodically to avoid retaining all the items and processing at the end.
   void ProcessAppendedItemsOnTheFly();
   void ProcessAppendedItems();
 #if DCHECK_IS_ON()
   bool ProcessAppendedItemsCalled() const { return !needs_process_; }
   bool needs_process_;
 #else
   bool ProcessAppendedItemsCalled() const { return true; }
 #endif
 
-  ListContainer<DisplayItem> items_;
+  RandomAccessListContainer<DisplayItem> items_;
   skia::RefPtr<SkPicture> picture_;
 
   scoped_ptr<SkPictureRecorder> recorder_;
   skia::RefPtr<SkCanvas> canvas_;
   bool use_cached_picture_;
   bool retain_individual_display_items_;
 
   gfx::Rect layer_rect_;
   bool all_items_are_suitable_for_gpu_rasterization_;
   int approximate_op_count_;
 
   // Memory usage due to the cached SkPicture.
   size_t picture_memory_usage_;
 
   // Memory usage due to external data held by display items.
   size_t external_memory_usage_;
 
   scoped_ptr<DiscardableImageMap> images_;
 
   friend class base::RefCountedThreadSafe<DisplayItemList>;
   friend class DiscardableImageMap::Iterator;
   FRIEND_TEST_ALL_PREFIXES(DisplayItemListTest, ApproximateMemoryUsage);
   DISALLOW_COPY_AND_ASSIGN(DisplayItemList);
 };
 
 }  // namespace cc
 
 #endif  // CC_PLAYBACK_DISPLAY_ITEM_LIST_H_