Moves maintaining root_window_for_new_windows_ to Shell

chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc

Index: chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc
diff --git a/chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc b/chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc
index 8ba36e527823adf2b97020be1d92966d349de438..a8bcfe9d7a74bf05ac5d5d3849a1a200c7c8261f 100644
--- a/chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc
+++ b/chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc
@@ -199,9 +199,9 @@ void ChromeNativeAppWindowViewsAuraAsh::OnBeforePanelWidgetInit(
                 ash::TYPE_APP_PANEL));
   } else if (ash::Shell::HasInstance() && use_default_bounds) {
     // Open a new panel on the target root.
-    init_params->context = ash::Shell::GetTargetRootWindow();
+    init_params->context = ash::Shell::GetRootWindowForNewWindows();
     init_params->bounds = gfx::Rect(GetPreferredSize());
-    wm::ConvertRectToScreen(ash::Shell::GetTargetRootWindow(),
+    wm::ConvertRectToScreen(ash::Shell::GetRootWindowForNewWindows(),
                             &init_params->bounds);
   }
 }