Implemented swipe to close in overview mode.

ash/wm/overview/window_selector_item.h

Index: ash/wm/overview/window_selector_item.h
diff --git a/ash/wm/overview/window_selector_item.h b/ash/wm/overview/window_selector_item.h
index 1ce6fa102353ad4036b1720e13bee4b9b35abf56..623fd91397470c217a08cba1ae530160bd2f9a69 100644
--- a/ash/wm/overview/window_selector_item.h
+++ b/ash/wm/overview/window_selector_item.h
@@ -73,6 +73,20 @@ class ASH_EXPORT WindowSelectorItem : public views::ButtonListener,
 
   const gfx::Rect& target_bounds() const { return target_bounds_; }
 
+  // Called when a touch scroll begin event occurs on this selector item.
+  void OnScrollBegin();
+
+  // Called when a touch scroll update event occurs on this selector item.
+  void OnScrollUpdate(int delta_x);
+
+  // Called when a touch scroll end event occurs on this selector item. This may
+  // cause the window to be closed.
+  void OnScrollEnd(int delta_x);
+
+  // Called when a touch fling event occurs on this selector item. This may
+  // cause the window to be closed.
+  void OnFling(int delta_x, float velocity_x);
+
   // views::ButtonListener:
   void ButtonPressed(views::Button* sender, const ui::Event& event) override;
 
@@ -106,6 +120,14 @@ class ASH_EXPORT WindowSelectorItem : public views::ButtonListener,
   // Updates the close buttons accessibility name.
   void UpdateCloseButtonAccessibilityName();
 
+  // Animates the |transform_window_| back to it's original overview mode
+  // position.
+  void ResetScrolledWindow();
+
+  // Returns the minimum distance at which a scroll gesture will cause this
+  // selector item to be closed.
+  int GetMinimumCloseDistance() const;
+
   // True if the item is being shown in the overview, false if it's being
   // filtered.
   bool dimmed_;