ui/gfx: Add MapRect and ExtractScale skia helper functions.

ui/gfx/skia_util.h

Index: ui/gfx/skia_util.h
diff --git a/ui/gfx/skia_util.h b/ui/gfx/skia_util.h
index 25c96d0370522e18bd9f8c2e771cc4ffd84917fc..fa6ba43dd4cf414da024bb63ebdc1febd690e893 100644
--- a/ui/gfx/skia_util.h
+++ b/ui/gfx/skia_util.h
@@ -88,6 +88,13 @@ GFX_EXPORT void ConvertSkiaToRGBA(const unsigned char* skia,
                                   int pixel_width,
                                   unsigned char* rgba);
 
+// Extracts the scale component from the matrix. Returns true if it succeeded
+// and false otherwise.
+GFX_EXPORT bool ExtractScale(const SkMatrix& matrix, SkSize* scale);
+
+// Applies the matrix to the rect and returns the resulting rect.
+GFX_EXPORT SkRect MapRect(const SkMatrix& matrix, const SkRect& src);
+
 }  // namespace gfx
 
 #endif  // UI_GFX_SKIA_UTIL_H_