Run athena on device

ash/root_window_controller.cc

Index: ash/root_window_controller.cc
diff --git a/ash/root_window_controller.cc b/ash/root_window_controller.cc
index 0e07dbe03e94cafc518cad419a90bb223e21f37c..eb97d251e9c807a27bc719f7913657b2691a61c8 100644
--- a/ash/root_window_controller.cc
+++ b/ash/root_window_controller.cc
@@ -284,17 +284,20 @@ void RootWindowController::CreateForVirtualKeyboardDisplay(
 // static
 RootWindowController* RootWindowController::ForShelf(
     const aura::Window* window) {
+  CHECK(Shell::HasInstance());
   return GetRootWindowController(window->GetRootWindow());
 }
 
 // static
 RootWindowController* RootWindowController::ForWindow(
     const aura::Window* window) {
+  CHECK(Shell::HasInstance());
   return GetRootWindowController(window->GetRootWindow());
 }
 
 // static
 RootWindowController* RootWindowController::ForTargetRootWindow() {
+  CHECK(Shell::HasInstance());
   return GetRootWindowController(Shell::GetTargetRootWindow());
 }