gesture recognizer: Recognizer rotation gestures.

ui/base/gestures/gesture_sequence.h

Index: ui/base/gestures/gesture_sequence.h
diff --git a/ui/base/gestures/gesture_sequence.h b/ui/base/gestures/gesture_sequence.h
index 0581f1ea9b6ea42f39a7dbb5df2d7a9f23ef7dc7..1420e533a53ba49d49e8c21e49914915655e8d41 100644
--- a/ui/base/gestures/gesture_sequence.h
+++ b/ui/base/gestures/gesture_sequence.h
@@ -120,6 +120,7 @@ class UI_EXPORT GestureSequence {
                              Gestures* gestures);
   void AppendPinchGestureUpdate(const GesturePoint& point,
                                 float scale,
+                                float rotation,
                                 Gestures* gestures);
   void AppendSwipeGesture(const GesturePoint& point,
                           int swipe_x,
@@ -186,6 +187,9 @@ class UI_EXPORT GestureSequence {
   gfx::Rect bounding_box_;
   gfx::Point bounding_box_last_center_;
 
+  // The angle of the diagonal of the bounding box with the X axis (in radians).
+  float bounding_box_diagonal_angle_;
+
   // For pinch, the 'distance' represents the diagonal distance of
   // |bounding_box_|.