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

ui/gfx/skia_util.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gfx/skia_util.h"
 
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkColorFilter.h"
 #include "third_party/skia/include/core/SkColorPriv.h"
 #include "third_party/skia/include/core/SkUnPreMultiply.h"
@@ skipping 205 matching lines @@
   }
 }
 
 void QuadFToSkPoints(const gfx::QuadF& quad, SkPoint points[4]) {
   points[0] = PointFToSkPoint(quad.p1());
   points[1] = PointFToSkPoint(quad.p2());
   points[2] = PointFToSkPoint(quad.p3());
   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