[ash-md] Cancels app-list (launcher) before entering overview

ash/app_list/app_list_presenter_delegate.cc

Index: ash/app_list/app_list_presenter_delegate.cc
diff --git a/ash/app_list/app_list_presenter_delegate.cc b/ash/app_list/app_list_presenter_delegate.cc
index 6d557d3b4d2e64a1872bd3ac3219cc88e30fcf06..8023dd7fdab4f2257785cf2a05d644743f00a95b 100644
--- a/ash/app_list/app_list_presenter_delegate.cc
+++ b/ash/app_list/app_list_presenter_delegate.cc
@@ -336,6 +336,11 @@ void AppListPresenterDelegate::OnShelfAlignmentChanged(WmWindow* root_window) {
     view_->SetBubbleArrow(GetBubbleArrow(view_->GetWidget()->GetNativeView()));
 }
 
+void AppListPresenterDelegate::OnOverviewModeStarting() {
+  if (is_visible_)
+    presenter_->Dismiss();
+}
+
 void AppListPresenterDelegate::OnMaximizeModeStarted() {
   // The "fullscreen" app-list is initialized as in a different type of window,
   // therefore we can't switch between the fullscreen status and the normal