Remove TransparentActivateWindowButton from Overview Mode

ash/wm/overview/scoped_transform_overview_window.cc

Index: ash/wm/overview/scoped_transform_overview_window.cc
diff --git a/ash/wm/overview/scoped_transform_overview_window.cc b/ash/wm/overview/scoped_transform_overview_window.cc
index 41205bf64ff8fa666af1e75383bee1332d400f6a..9184e68d37e3e3a965ce4d258d2a99cac470c406 100644
--- a/ash/wm/overview/scoped_transform_overview_window.cc
+++ b/ash/wm/overview/scoped_transform_overview_window.cc
@@ -167,8 +167,6 @@ TransientDescendantIteratorRange GetTransientTreeIterator(
 ScopedTransformOverviewWindow::ScopedTransformOverviewWindow(
         aura::Window* window)
     : window_(window),
-      activate_button_(new TransparentActivateWindowButton(
-          window_->GetRootWindow(), this)),
       minimized_(window->GetProperty(aura::client::kShowStateKey) ==
                  ui::SHOW_STATE_MINIMIZED),
       ignored_by_shelf_(wm::GetWindowState(window)->ignored_by_shelf()),
@@ -302,10 +300,6 @@ void ScopedTransformOverviewWindow::SetOpacity(float opacity) {
   }
 }
 
-void ScopedTransformOverviewWindow::Select() {
-  wm::GetWindowState(window_)->Activate();
-}
-
 void ScopedTransformOverviewWindow::Close() {
   aura::Window* window = GetTransientRoot(window_);
   views::Widget::GetWidgetForNativeView(window)->Close();