Repaint on interest rect change

third_party/WebKit/Source/platform/graphics/paint/PaintController.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 PaintController_h
 #define PaintController_h
 
 #include "platform/PlatformExport.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/geometry/IntRect.h"
@@ skipping 103 matching lines @@
     // shared with the embedder after copying to WebPaintController.
     // Should only be called right after commitNewDisplayItems.
     size_t approximateUnsharedMemoryUsage() const;
 
     // Get the artifact generated after the last commit.
     const PaintArtifact& paintArtifact() const;
     const DisplayItemList& displayItemList() const { return paintArtifact().displayItemList(); }
     const Vector<PaintChunk>& paintChunks() const { return paintArtifact().paintChunks(); }
 
     bool clientCacheIsValid(DisplayItemClient) const;
+    bool cacheIsEmpty() const { return m_currentPaintArtifact.isEmpty(); }
 
     bool displayItemConstructionIsDisabled() const { return m_constructionDisabled; }
     void setDisplayItemConstructionIsDisabled(const bool disable) { m_constructionDisabled = disable; }
 
     bool textPainted() const { return m_textPainted; }
     void setTextPainted() { m_textPainted = true; }
     bool imagePainted() const { return m_imagePainted; }
     void setImagePainted() { m_imagePainted = true; }
 
     // Returns displayItemList added using createAndAppend() since beginning or
@@ skipping 124 matching lines @@
     // easily find where the duplicated ids are from.
     DisplayItemIndicesByClientMap m_newDisplayItemIndicesByClient;
 #endif
 
     OwnPtr<Vector<String>> m_trackedPaintInvalidationObjects;
 };
 
 } // namespace blink
 
 #endif // PaintController_h