cc: Implement RemoveLast for DisplayItemList.

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 35 matching lines @@
 
   template <typename DisplayItemType>
   DisplayItemType* CreateAndAppendItem() {
 #if DCHECK_IS_ON()
     needs_process_ = true;
 #endif
     ProcessAppendedItemsOnTheFly();
     return items_.AllocateAndConstruct<DisplayItemType>();
   }
 
+  // Removes the last item. This cannot be called on lists with cached pictures
+  // (since the data may already have been incorporated into cached picture
+  // sizes, etc).
+  void RemoveLast();
+
   // Called after all items are appended, to process the items and, if
   // applicable, create an internally cached SkPicture.
   void Finalize();
 
   bool IsSuitableForGpuRasterization() const;
   int ApproximateOpCount() const;
   size_t PictureMemoryUsage() const;
 
   scoped_refptr<base::trace_event::ConvertableToTraceFormat> AsValue() const;
 
@@ skipping 40 matching lines @@
 
   friend class base::RefCountedThreadSafe<DisplayItemList>;
   friend class PixelRefMap::Iterator;
   FRIEND_TEST_ALL_PREFIXES(DisplayItemListTest, PictureMemoryUsage);
   DISALLOW_COPY_AND_ASSIGN(DisplayItemList);
 };
 
 }  // namespace cc
 
 #endif  // CC_PLAYBACK_DISPLAY_ITEM_LIST_H_