Add in gesture for immersive mode

ash/wm/gestures/edge_gesture_handler.h

Index: ash/wm/gestures/edge_gesture_handler.h
diff --git a/ash/wm/gestures/edge_gesture_handler.h b/ash/wm/gestures/edge_gesture_handler.h
index 304099ecaa4da6078dd22ac4ce634c119f1d673a..d3e539f3c88bb24e30305691a8316ce387223a30 100644
--- a/ash/wm/gestures/edge_gesture_handler.h
+++ b/ash/wm/gestures/edge_gesture_handler.h
@@ -47,6 +47,11 @@ class EdgeGestureHandler {
   // events from this gesture should be sent.
   bool HandleLauncherControl(const ui::GestureEvent& event);
 
+  // Handle events meant for engaging immerisive mode. Returns true when no
+  // further events from this gesture should be sent.
+  bool HandleImmersiveControl(aura::Window* target,
+                              const ui::GestureEvent& event);
+
   // Handle a gesture begin event.
   bool HandleEdgeGestureStart(aura::Window* target,
                               const ui::GestureEvent& event);
@@ -73,6 +78,9 @@ class EdgeGestureHandler {
   // launcher.
   bool IsGestureInLauncherOrientation(const ui::GestureEvent& event);
 
+  // Test if the gesture orientation makes sense to be engaging immersive mode.
+  bool IsGestureInImmersiveOrientation(const ui::GestureEvent& event);
+
   // Which edges the gesture is close to.
   unsigned int start_location_;