[SPv2] Rasterization invalidation

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"
@@ skipping 12 matching lines @@
     WTF_MAKE_NONCOPYABLE(PaintChunker);
 public:
     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 incrementDisplayItemIndex(const DisplayItem&);
-    void decrementDisplayItemIndex();
+    // Returns true if a new chunk is created.
+    bool incrementDisplayItemIndex(const DisplayItem&);
+    // Returns true if the last chunk is removed.
+    bool decrementDisplayItemIndex();
 
-    const PaintChunk& lastChunk() const { return m_chunks.last(); }
+    PaintChunk& paintChunkAt(size_t i) { return m_chunks[i]; }
+    size_t lastChunkIndex() const { return m_chunks.isEmpty() ? kNotFound : m_chunks.size() - 1; }
+    PaintChunk& lastChunk() { return m_chunks.last(); }
 
     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