Track the region where text is painted.

Source/core/platform/graphics/skia/SkiaFontWin.h

 /*
  * Copyright (c) 2008, Google Inc. All rights reserved.
  * 
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  * 
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 17 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef SkiaFontWin_h
 #define SkiaFontWin_h
 
 #include <windows.h>
 #include <usp10.h>
 
 struct SkPoint;
+struct SkRect;
 
 namespace WebCore {
 
 class FontPlatformData;
 class GraphicsContext;
 
 // Note that the offsets parameter is optional. If not null it represents a
 // per glyph offset (such as returned by ScriptPlace Windows API function).
 void paintSkiaText(GraphicsContext*,
                    const FontPlatformData&,
                    int numGlyphs,
                    const WORD* glyphs,
                    const int* advances,
                    const GOFFSET* offsets,
-                   const SkPoint* origin);
+                   const SkPoint& origin,
+                   const SkRect& textRect);
 
 // Note that the offsets parameter is optional. If not null it represents a
 // per glyph offset (such as returned by ScriptPlace Windows API function).
 // Note: this is less efficient than calling the version with FontPlatformData,
 // as that caches the SkTypeface object.
 void paintSkiaText(GraphicsContext*,
                    HFONT,
                    int numGlyphs,
                    const WORD* glyphs,
                    const int* advances,
                    const GOFFSET* offsets,
-                   const SkPoint* origin);
+                   const SkPoint& origin,
+                   const SkRect& textRect);
 
 }  // namespace WebCore
 
 #endif  // SkiaFontWin_h