Merge Blink code to cache SkTextBlob

sky/engine/core/rendering/InlineTextBox.h

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 143 matching lines @@
     virtual float positionForOffset(int offset) const;
 
     bool containsCaretOffset(int offset) const; // false for offset after line break
 
     // Fills a vector with the pixel width of each character.
     void characterWidths(Vector<float>&) const;
 
 private:
     InlineTextBox* m_prevTextBox; // The previous box that also uses our RenderObject
     InlineTextBox* m_nextTextBox; // The next box that also uses our RenderObject
+    TextBlobPtr m_cachedTextBlob;
 
     int m_start;
     unsigned short m_len;
 
     unsigned short m_truncation; // Where to truncate when text overflow is applied.  We use special constants to
                       // denote no truncation (the whole run paints) and full truncation (nothing paints at all).
 
     unsigned underlinePaintStart(const CompositionUnderline&);
     unsigned underlinePaintEnd(const CompositionUnderline&);
 
@@ skipping 24 matching lines @@
 
 inline AffineTransform InlineTextBox::rotation(const FloatRect& boxRect, RotationDirection rotationDirection)
 {
     return rotationDirection == Clockwise ? AffineTransform(0, 1, -1, 0, boxRect.x() + boxRect.maxY(), boxRect.maxY() - boxRect.x())
         : AffineTransform(0, -1, 1, 0, boxRect.x() - boxRect.maxY(), boxRect.x() + boxRect.maxY());
 }
 
 } // namespace blink
 
 #endif  // SKY_ENGINE_CORE_RENDERING_INLINETEXTBOX_H_