Split Screen mode implementation

athena/wm/bezel_controller.h

Index: athena/wm/bezel_controller.h
diff --git a/athena/wm/bezel_controller.h b/athena/wm/bezel_controller.h
index 30fe974f6cbb7d3fddf57bab02532d6684d739b4..8dcfdb94f46645aafe63eb473b127711f4aa771d 100644
--- a/athena/wm/bezel_controller.h
+++ b/athena/wm/bezel_controller.h
@@ -35,12 +35,16 @@ class BezelController : public ui::EventHandler {
     virtual ~ScrollDelegate() {}
 
     // Beginning of a bezel scroll gesture started from the |bezel|.
+    // |delta| is the difference between the x-coordinate of the current scroll
+    // position and the bezel. It will be zero or negative for the right bezel.
     virtual void ScrollBegin(Bezel bezel, float delta) = 0;
 
     // End of the current bezel scroll
     virtual void ScrollEnd() = 0;
 
     // Update of the scroll position for the currently active bezel scroll.
+    // |delta| is the difference between the x-coordinate of the current scroll
+    // position and the bezel. It will be zero or negative for the right bezel.

[oshima, 2014/08/08 16:45:34]

nit: you may refer to the comment in ScrollBegin for |delta| instead of
repeating the comment.

[mfomitchev, 2014/08/08 17:40:50]

Done.

     virtual void ScrollUpdate(float delta) = 0;
 
     // Should return false if the delegate isn't going to react to the scroll
@@ -67,11 +71,10 @@ class BezelController : public ui::EventHandler {
     BEZEL_SCROLLING_TWO_FINGERS,
   };
 
-  // Calculates the distance from |position| to the |bezel|.
-  float GetDistance(const gfx::PointF& position, Bezel bezel);
-
-  // |scroll_position| only needs to be passed in the scrolling state
-  void SetState(State state, const gfx::PointF& scroll_position);
+  void SetState(State state);
+  // |scroll_delta| only needs to be passed when |state| is one of the
+  // BEZEL_SROLLING states.
+  void SetState(State state, float scroll_delta);
 
   // Returns the bezel corresponding to the |location| or BEZEL_NONE if the
   // location is outside of the bezel area.