Track the region where text is painted.

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

Index: Source/core/platform/graphics/skia/SkiaFontWin.h
diff --git a/Source/core/platform/graphics/skia/SkiaFontWin.h b/Source/core/platform/graphics/skia/SkiaFontWin.h
index f4d34f5f85e6d2100b8787da4be0eb688893e55a..926d29dc967729484009b08f1af3f17e9d8a41ac 100644
--- a/Source/core/platform/graphics/skia/SkiaFontWin.h
+++ b/Source/core/platform/graphics/skia/SkiaFontWin.h
@@ -35,6 +35,7 @@
 #include <usp10.h>
 
 struct SkPoint;
+struct SkRect;
 
 namespace WebCore {
 
@@ -49,7 +50,8 @@ void paintSkiaText(GraphicsContext*,
                    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).
@@ -61,7 +63,8 @@ void paintSkiaText(GraphicsContext*,
                    const WORD* glyphs,
                    const int* advances,
                    const GOFFSET* offsets,
-                   const SkPoint* origin);
+                   const SkPoint& origin,
+                   const SkRect& textRect);
 
 }  // namespace WebCore