Implemented swipe to close in overview mode.

ash/wm/overview/window_selector_controller.h

Index: ash/wm/overview/window_selector_controller.h
diff --git a/ash/wm/overview/window_selector_controller.h b/ash/wm/overview/window_selector_controller.h
index 8d4a625e13e72ec9aab2c160e03e59900d2648f6..3a879040165aa16fec6ca01632160d2eaa7112b9 100644
--- a/ash/wm/overview/window_selector_controller.h
+++ b/ash/wm/overview/window_selector_controller.h
@@ -48,6 +48,8 @@ class ASH_EXPORT WindowSelectorController
   // are visible during overview mode.
   bool IsRestoringMinimizedWindows() const;
 
+  bool swipe_to_close_disabled() const { return swipe_to_close_disabled_; }
+
   // WindowSelectorDelegate:
   void OnSelectionEnded() override;
 
@@ -60,6 +62,9 @@ class ASH_EXPORT WindowSelectorController
   scoped_ptr<WindowSelector> window_selector_;
   base::Time last_selection_time_;
 
+  // Tracks whether the "Swipe-to-close" feature is disabled.
+  bool swipe_to_close_disabled_;
+
   DISALLOW_COPY_AND_ASSIGN(WindowSelectorController);
 };