Revert of PaintChunk::id

third_party/WebKit/Source/platform/graphics/paint/PaintChunker.h

 // Copyright 2015 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 PaintChunker_h
 #define PaintChunker_h
 
 #include "platform/PlatformExport.h"
-#include "platform/graphics/paint/DisplayItem.h"
 #include "platform/graphics/paint/PaintChunk.h"
 #include "platform/graphics/paint/PaintChunkProperties.h"
 #include "wtf/Allocator.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
 // Accepts information about changes to |PaintChunkProperties| as drawings are
 // accumulated, and produces a series of paint chunks: contiguous ranges of the
 // display list with identical |PaintChunkProperties|.
 class PLATFORM_EXPORT PaintChunker final {
     DISALLOW_NEW();
     WTF_MAKE_NONCOPYABLE(PaintChunker);
 public:
+    enum ItemBehavior {
+        // Can be combined with adjacent items when building chunks.
+        DefaultBehavior = 0,
+
+        // Item requires its own paint chunk.
+        RequiresSeparateChunk,
+    };
+
     PaintChunker();
     ~PaintChunker();
 
     bool isInInitialState() const { return m_chunks.isEmpty() && m_currentProperties == PaintChunkProperties(); }
 
     const PaintChunkProperties& currentPaintChunkProperties() const { return m_currentProperties; }
-    void updateCurrentPaintChunkProperties(const PaintChunk::Id*, const PaintChunkProperties&);
+    void updateCurrentPaintChunkProperties(const PaintChunkProperties&);
 
-    void incrementDisplayItemIndex(const DisplayItem&);
+    void incrementDisplayItemIndex(ItemBehavior);
     void decrementDisplayItemIndex();
 
     void clear();
 
     // Releases the generated paint chunk list and resets the state of this
     // object.
     Vector<PaintChunk> releasePaintChunks();
 
 private:
-    enum ItemBehavior {
-        // Can be combined with adjacent items when building chunks.
-        DefaultBehavior = 0,
-
-        // Item requires its own paint chunk.
-        RequiresSeparateChunk,
-    };
-
     Vector<PaintChunk> m_chunks;
     Vector<ItemBehavior> m_chunkBehavior;
-    Optional<PaintChunk::Id> m_currentChunkId;
     PaintChunkProperties m_currentProperties;
 };
 
 } // namespace blink
 
 #endif // PaintChunker_h