Move visual rect unioning between paired items to cc::DisplayItemList.

third_party/WebKit/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 222 matching lines @@
     // Size of this object in memory, used to move it with memcpy.
     // This is not sizeof(*this), because it needs to account for the size of
     // the derived class (i.e. runtime type). Derived classes are expected to
     // supply this to the DisplayItem constructor.
     size_t derivedSize() const { return m_derivedSize; }
 
     // For PaintController only. Painters should use DisplayItemCacheSkipper instead.
     void setSkippedCache() { m_skippedCache = true; }
     bool skippedCache() const { return m_skippedCache; }
 
+    // TODO(wkorman): Only DrawingDisplayItem needs the visual rect argument.
+    // Consider refactoring class hierarchy to make this more explicit.
     virtual void appendToWebDisplayItemList(const IntRect&, WebDisplayItemList*) const { }
 
     // See comments of enum Type for usage of the following macros.
 #define DEFINE_CATEGORY_METHODS(Category) \
     static bool is##Category##Type(Type type) { return type >= Category##First && type <= Category##Last; } \
     bool is##Category() const { return is##Category##Type(getType()); }
 
 #define DEFINE_CONVERSION_METHODS(Category1, category1, Category2, category2) \
     static Type category1##TypeTo##Category2##Type(Type type) \
     { \
@@ skipping 125 matching lines @@
     bool isEndAndPairedWith(DisplayItem::Type otherType) const override = 0;
 #endif
 
 private:
     bool isEnd() const final { return true; }
 };
 
 } // namespace blink
 
 #endif // DisplayItem_h