Move use of DisplayItemList's vector behind an explicit DisplayItems interface.

Source/platform/graphics/paint/DisplayItemList.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 DisplayItemList_h
 #define DisplayItemList_h
 
 #include "platform/PlatformExport.h"
 #include "platform/graphics/paint/DisplayItem.h"
+#include "platform/graphics/paint/DisplayItems.h"
 #include "wtf/HashMap.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
 class GraphicsContext;
 
-typedef Vector<OwnPtr<DisplayItem>> DisplayItems;
-
 class PLATFORM_EXPORT DisplayItemList {
     WTF_MAKE_NONCOPYABLE(DisplayItemList);
     WTF_MAKE_FAST_ALLOCATED(DisplayItemList);
 public:
     static PassOwnPtr<DisplayItemList> create()
     {
         return adoptPtr(new DisplayItemList());
     }
 
     // These methods are called during paint invalidation.
@@ skipping 17 matching lines @@
 
     bool clientCacheIsValid(DisplayItemClient) const;
 
     // Commits the new display items and plays back the updated display items into the given context.
     void commitNewDisplayItemsAndReplay(GraphicsContext& context)
     {
         commitNewDisplayItems();
         replay(context);
     }
 
+    void commitNewDisplayItemsAndAppendToWebDisplayItemList(WebDisplayItemList*);
+
     bool displayItemConstructionIsDisabled() const { return m_constructionDisabled; }
     void setDisplayItemConstructionIsDisabled(const bool disable) { m_constructionDisabled = disable; }
 
 #if ENABLE(ASSERT)
     size_t newDisplayItemsSize() const { return m_newDisplayItems.size(); }
 #endif
 
 #ifndef NDEBUG
     void showDebugData() const;
 #endif
@@ skipping 12 matching lines @@
     void updateValidlyCachedClientsIfNeeded() const;
 
 #ifndef NDEBUG
     WTF::String displayItemsAsDebugString(const DisplayItems&) const;
 #endif
 
     // Indices into PaintList of all DrawingDisplayItems and BeginSubtreeDisplayItems of each client.
     // Temporarily used during merge to find out-of-order display items.
     using DisplayItemIndicesByClientMap = HashMap<DisplayItemClient, Vector<size_t>>;
 
-    static size_t findMatchingItemFromIndex(const DisplayItem&, DisplayItem::Type matchingType, const DisplayItemIndicesByClientMap&, const DisplayItems&);
-    static void addItemToIndex(const DisplayItem&, size_t index, DisplayItemIndicesByClientMap&);
-    size_t findOutOfOrderCachedItem(size_t& currentDisplayItemsIndex, const DisplayItem&, DisplayItem::Type, DisplayItemIndicesByClientMap&);
-    size_t findOutOfOrderCachedItemForward(size_t& currentDisplayItemsIndex, const DisplayItem&, DisplayItem::Type, DisplayItemIndicesByClientMap&);
+    static size_t findMatchingItemFromIndex(const DisplayItem::Id&, DisplayItem::Type matchingType, const DisplayItemIndicesByClientMap&, const DisplayItems&);
+    static void addItemToIndex(DisplayItemClient, DisplayItem::Type, size_t index, DisplayItemIndicesByClientMap&);
+    DisplayItems::Iterator findOutOfOrderCachedItem(DisplayItems::Iterator& currentIt, const DisplayItem::Id&, DisplayItem::Type, DisplayItemIndicesByClientMap&);
+    DisplayItems::Iterator findOutOfOrderCachedItemForward(DisplayItems::Iterator& currentIt, const DisplayItem::Id&, DisplayItem::Type, DisplayItemIndicesByClientMap&);
 
 #if ENABLE(ASSERT)
     // The following two methods are for checking under-invalidations
     // (when RuntimeEnabledFeatures::slimmingPaintUnderInvalidationCheckingEnabled).
-    void checkCachedDisplayItemIsUnchanged(const DisplayItem&, DisplayItemIndicesByClientMap&);
+    void checkCachedDisplayItemIsUnchanged(const DisplayItems::ItemHandle&, DisplayItemIndicesByClientMap&);
     void checkNoRemainingCachedDisplayItems();
 #endif
 
     void replay(GraphicsContext&) const;
 
     DisplayItems m_currentDisplayItems;
     DisplayItems m_newDisplayItems;
 
     // Contains all clients having valid cached paintings if updated.
     // It's lazily updated in updateValidlyCachedClientsIfNeeded().
@@ skipping 24 matching lines @@
     // This is used to check duplicated ids during add(). We could also check during
     // updatePaintList(), but checking during add() helps developer easily find where
     // the duplicated ids are from.
     DisplayItemIndicesByClientMap m_newDisplayItemIndicesByClient;
 #endif
 };
 
 } // namespace blink
 
 #endif // DisplayItemList_h