Canvas2d: Make the intersection computation O(1) instead of O(n) in ClipList.

third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2DState.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 CanvasRenderingContext2DState_h
 #define CanvasRenderingContext2DState_h
 
 #include "core/css/CSSFontSelectorClient.h"
 #include "modules/canvas2d/ClipList.h"
 #include "platform/fonts/Font.h"
@@ skipping 57 matching lines @@
     // setTransform returns true iff transform is invertible;
     void setTransform(const AffineTransform&);
     void resetTransform();
     AffineTransform transform() const { return m_transform; }
     bool isTransformInvertible() const { return m_isTransformInvertible; }
 
     void clipPath(const SkPath&, AntiAliasingMode);
     bool hasClip() const { return m_hasClip; }
     bool hasComplexClip() const { return m_hasComplexClip; }
     void playbackClips(SkCanvas* canvas) const { m_clipList.playback(canvas); }
-    SkPath intersectPathWithClip(const SkPath& path) const { return m_clipList.intersectPathWithClip(path); }
+    const SkPath& getCurrentClipPath() const { return m_clipList.getCurrentClipPath(); }
 
     void setFont(const Font&, CSSFontSelector*);
     const Font& font() const;
     bool hasRealizedFont() const { return m_realizedFont; }
     void setUnparsedFont(const String& font) { m_unparsedFont = font; }
     const String& unparsedFont() const { return m_unparsedFont; }
 
     void setFilter(PassRefPtrWillBeRawPtr<CSSValue>);
     void setUnparsedFilter(const String& filterString) { m_unparsedFilter = filterString; }
     const String& unparsedFilter() const { return m_unparsedFilter; }
@@ skipping 137 matching lines @@
 
     bool m_imageSmoothingEnabled;
     SkFilterQuality m_imageSmoothingQuality;
 
     ClipList m_clipList;
 };
 
 } // namespace blink
 
 #endif