Adds function to invert a transform to ui::Transform

ui/gfx/transform.h

Index: ui/gfx/transform.h
diff --git a/ui/gfx/transform.h b/ui/gfx/transform.h
index 483aa564652c9cf47d2b0ae49d475406a3a9a596..4f830d59cdd07165dd3faf80a5bcbad7565937d7 100644
--- a/ui/gfx/transform.h
+++ b/ui/gfx/transform.h
@@ -69,6 +69,9 @@ class UI_EXPORT Transform {
   // Does the transformation change anything?
   bool HasChange() const;
 
+  // Inverts the transform which is passed in. Returns true if successful.

[sky, 2011/10/24 21:09:00]

This description is a bit misleading. I think you mean:
Inverts this transform storing the result in |transform|. Returns true if this
matrix can be inverted.

+  bool GetInverse(Transform* transform) const;
+
   // Applies the transformation on the point. Returns true if the point is
   // transformed successfully.
   void TransformPoint(gfx::Point3f& point) const;