Allow the computation of inflated bounds for non matrix transform operations.

ui/gfx/box_f.h

Index: ui/gfx/box_f.h
diff --git a/ui/gfx/box_f.h b/ui/gfx/box_f.h
index 11770ee58acaa224a3d4984dd8ab2b9d7faa6fcc..73e0972f662318cb10ea6daf9804a584d7e25f64 100644
--- a/ui/gfx/box_f.h
+++ b/ui/gfx/box_f.h
@@ -99,6 +99,11 @@ class GFX_EXPORT BoxF {
   // |origin_|.
   void ExpandTo(const Point3F& point);
 
+  // Expands |this| to contain the given box, if necessary. Please note, even
+  // if |this| is empty, after the function |this| will continue to contain its
+  // |origin_|.
+  void ExpandTo(const BoxF& box);
+
  private:
   // Expands the box to contain the two given points. It is required that each
   // component of |min| is less than or equal to the corresponding component in