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

ui/gfx/skia_util.cc

Index: ui/gfx/skia_util.cc
diff --git a/ui/gfx/skia_util.cc b/ui/gfx/skia_util.cc
index d3a1ac8874c0670717c732dd8d482f9d5c85d21b..db2c8930c38df8deedb7b727945dfd0b80d431d0 100644
--- a/ui/gfx/skia_util.cc
+++ b/ui/gfx/skia_util.cc
@@ -223,4 +223,21 @@ void QuadFToSkPoints(const gfx::QuadF& quad, SkPoint points[4]) {
   points[3] = PointFToSkPoint(quad.p4());
 }
 
+bool ExtractScale(const SkMatrix& matrix, SkSize* scale) {
+  *scale = SkSize::Make(matrix.getScaleX(), matrix.getScaleY());
+  if (matrix.getType() & SkMatrix::kAffine_Mask) {
+    if (!matrix.decomposeScale(scale)) {
+      scale->set(1.f, 1.f);
+      return false;
+    }
+  }
+  return true;
+}
+
+SkRect MapRect(const SkMatrix& matrix, const SkRect& src) {

[danakj, 2015/12/03 00:12:35]

I question why you're using an SkMatrix and not a gfx::Transform.

+  SkRect dst;
+  matrix.mapRect(&dst, src);
+  return dst;
+}
+
 }  // namespace gfx