Add detection for rotation and flip overlay transforms

cc/base/math_util.h

Index: cc/base/math_util.h
diff --git a/cc/base/math_util.h b/cc/base/math_util.h
index 56fdd1774eac48e616aa944fb0678b774402eb95..583aa4fcdd7c7d55182c31477eba8af72bd51fc4 100644
--- a/cc/base/math_util.h
+++ b/cc/base/math_util.h
@@ -33,6 +33,7 @@ class RectF;
 class Transform;
 class Vector2dF;
 class Vector2d;
+class Vector3dF;
 }
 
 namespace cc {
@@ -240,6 +241,12 @@ class CC_EXPORT MathUtil {
   // If the value is inf, returns max double/float representation.
   static double AsDoubleSafely(double value);
   static float AsFloatSafely(float value);
+
+  // Returns vector that x axis (1,0,0) transforms to under given transform

[danakj, 2015/05/12 23:32:15]

nit: period

[halliwell, 2015/05/13 00:49:50]

Done.

+  static gfx::Vector3dF GetXAxis(const gfx::Transform& transform);
+
+  // Returns vector that y axis (0,1,0) transforms to under given transform

[danakj, 2015/05/12 23:32:15]

dittonit

[halliwell, 2015/05/13 00:49:50]

Done.

+  static gfx::Vector3dF GetYAxis(const gfx::Transform& transform);
 };
 
 }  // namespace cc