[ash-md] Fixes z-order to get context menus above overview items

Changes the parent of search widget labels and close buttons in overview
mode to be kShellWindowId_StatusContainer which is still above all
windows but below menus and screen overlays.

BUG=629039

Review-Url: https://codereview.chromium.org/2154323002
Cr-Commit-Position: refs/heads/master@{#406040}

ash/common/wm/overview/window_selector.cc

@@ -207,7 +207,7 @@ views::Widget* CreateTextFilter(views::TextfieldController* controller,
   params.bounds = GetTextFilterPosition(root_window);
   *text_filter_bottom = params.bounds.bottom();
   root_window->GetRootWindowController()->ConfigureWidgetInitParamsForContainer(
-      widget, kShellWindowId_OverlayContainer, &params);
+      widget, kShellWindowId_StatusContainer, &params);
   widget->Init(params);
 
   // Use |container| to specify the padding surrounding the text and to give

ash/common/wm/overview/window_selector_item.cc

@@ -294,7 +294,7 @@ WindowSelectorItem::WindowSelectorItem(WmWindow* window,
     close_button_widget_.reset(new views::Widget);
     close_button_widget_->set_focus_on_creation(false);
     window->GetRootWindowController()->ConfigureWidgetInitParamsForContainer(
-        close_button_widget_.get(), kShellWindowId_OverlayContainer, &params);
+        close_button_widget_.get(), kShellWindowId_StatusContainer, &params);
     close_button_widget_->Init(params);
     close_button_->SetVisible(false);
     close_button_widget_->SetContentsView(close_button_);
@@ -534,7 +534,7 @@ void WindowSelectorItem::CreateWindowLabel(const base::string16& title) {
   window_label_->set_focus_on_creation(false);
   root_window_->GetRootWindowController()
       ->ConfigureWidgetInitParamsForContainer(
-          window_label_.get(), kShellWindowId_OverlayContainer, &params);
+          window_label_.get(), kShellWindowId_StatusContainer, &params);
   window_label_->Init(params);
   window_label_button_view_ = new OverviewLabelButton(this, title);
   window_label_button_view_->SetBorder(views::Border::NullBorder());