Subtree caching implementation in blink-core

Source/platform/graphics/paint/DisplayItem.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 DisplayItem_h
 #define DisplayItem_h
 
 #include "platform/PlatformExport.h"
 #include "platform/graphics/ContiguousContainer.h"
 #include "platform/graphics/paint/DisplayItemClient.h"
@@ skipping 203 matching lines @@
 
     // Ids are for matching new DisplayItems with existing DisplayItems.
     struct Id {
         Id(const DisplayItemClient client, const Type type, const unsigned scope)
             : client(client)
             , type(type)
             , scope(scope) { }
 
         bool matches(const DisplayItem& item) const
         {
-            // We should always convert to non-cached types before matching.
-            ASSERT(!isCachedType(item.m_type));
-            ASSERT(!isCachedType(type));
             return client == item.m_client
                 && type == item.m_type
                 && scope == item.m_scope;
         }
 
         const DisplayItemClient client;
         const Type type;
         const unsigned scope;
     };
 
@@ skipping 162 matching lines @@
     bool isEndAndPairedWith(DisplayItem::Type otherType) const override = 0;
 #endif
 
 private:
     bool isEnd() const final { return true; }
 };
 
 } // namespace blink
 
 #endif // DisplayItem_h