Implemented swipe to close in overview mode.

ash/wm/overview/window_selector_item.cc

Index: ash/wm/overview/window_selector_item.cc
diff --git a/ash/wm/overview/window_selector_item.cc b/ash/wm/overview/window_selector_item.cc
index 7350ebdeed59394c0325f3d91ffa0909bd9110ed..b086c92cee77a7f222f3f24503ee27bc9f8fd4b2 100644
--- a/ash/wm/overview/window_selector_item.cc
+++ b/ash/wm/overview/window_selector_item.cc
@@ -212,7 +212,6 @@ void WindowSelectorItem::RemoveWindow(const aura::Window* window) {
   }
   CHECK(window_found);
 
-
   // If empty WindowSelectorItem will be destroyed immediately after this by
   // its owner.
   if (empty())
@@ -252,6 +251,7 @@ void WindowSelectorItem::SetBounds(aura::Window* root_window,
   // SetItemBounds is called before UpdateCloseButtonLayout so the close button
   // can properly use the updated windows bounds.
   UpdateCloseButtonLayout(animation_type);
+  SetCloseWindowDistanceMinimum(target_bounds_.size().width() / 2);
   UpdateSelectorButtons();
 }
 
@@ -295,12 +295,36 @@ void WindowSelectorItem::OnWindowTitleChanged(aura::Window* window) {
   UpdateSelectorButtons();
 }
 
+void WindowSelectorItem::Scroll(int delta_x) {
+  for (TransformWindows::iterator iter = transform_windows_.begin();
+       iter != transform_windows_.end();
+       iter++) {
+    (*iter)->Scroll(delta_x);
+  }
+}
+
+void WindowSelectorItem::CancelScroll() {
+  for (TransformWindows::iterator iter = transform_windows_.begin();
+       iter != transform_windows_.end();
+       iter++) {
+    (*iter)->CancelScroll();
+  }
+}
+
 void WindowSelectorItem::Select() {
   aura::Window* selection_window = SelectionWindow();
   if (selection_window)
     wm::GetWindowState(selection_window)->Activate();
 }
 
+void WindowSelectorItem::Close() {
+  for (TransformWindows::iterator iter = transform_windows_.begin();
+       iter != transform_windows_.end();
+       iter++) {
+    (*iter)->Close();
+  }
+}
+
 void WindowSelectorItem::SetItemBounds(aura::Window* root_window,
                                        const gfx::Rect& target_bounds,
                                        OverviewAnimationType animation_type) {
@@ -401,6 +425,16 @@ void WindowSelectorItem::CreateWindowLabel(const base::string16& title) {
   window_label_->Show();
 }
 
+void WindowSelectorItem::SetCloseWindowDistanceMinimum(int distance) {
+  selector_item_activate_window_button_->SetCloseWindowDistanceMinimum(
+      distance);
+  for (TransformWindows::iterator iter = transform_windows_.begin();
+       iter != transform_windows_.end();
+       ++iter) {
+    (*iter)->activate_button()->SetCloseWindowDistanceMinimum(distance);
+  }
+}
+
 void WindowSelectorItem::UpdateSelectorButtons() {
   CHECK(!transform_windows_.empty());