ash: Add RootWindowHostFactory class.

chrome/browser/ui/ash/chrome_shell_delegate.cc

Index: chrome/browser/ui/ash/chrome_shell_delegate.cc
diff --git a/chrome/browser/ui/ash/chrome_shell_delegate.cc b/chrome/browser/ui/ash/chrome_shell_delegate.cc
index e717d1d524010119e38f44948bf1dd0d45454bfa..62f4ab33b5a14ddd3687a6eb5b47ecc2060de51f 100644
--- a/chrome/browser/ui/ash/chrome_shell_delegate.cc
+++ b/chrome/browser/ui/ash/chrome_shell_delegate.cc
@@ -6,6 +6,7 @@
 
 #include "ash/launcher/launcher_types.h"
 #include "ash/magnifier/magnifier_constants.h"
+#include "ash/root_window_delegate.h"
 #include "ash/system/tray/system_tray_delegate.h"
 #include "ash/wm/stacking_controller.h"
 #include "ash/wm/window_util.h"
@@ -551,6 +552,10 @@ bool ChromeShellDelegate::IsSearchKeyActingAsFunctionKey() const {
 #endif
 }
 
+aura::RootWindowDelegate* ChromeShellDelegate::CreateRootWindowDelegate() {
+  return ash::RootWindowDelegate::Create();
+}
+
 void ChromeShellDelegate::Observe(int type,
                                   const content::NotificationSource& source,
                                   const content::NotificationDetails& details) {