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 2e42d8546071b116d9b8c821163045a4ef175185..b313e17903a94d8f9ef585c88b5b1b23dcf55656 100644
--- a/chrome/browser/ui/ash/chrome_shell_delegate.cc
+++ b/chrome/browser/ui/ash/chrome_shell_delegate.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/browser/ui/ash/chrome_shell_delegate.h"
 
+#include "ash/host/root_window_host_factory.h"
 #include "ash/launcher/launcher_types.h"
 #include "ash/magnifier/magnifier_constants.h"
 #include "ash/system/tray/system_tray_delegate.h"
@@ -548,6 +549,10 @@ bool ChromeShellDelegate::IsSearchKeyActingAsFunctionKey() const {
 #endif
 }
 
+ash::RootWindowHostFactory* ChromeShellDelegate::CreateRootWindowHostFactory() {
+  return ash::RootWindowHostFactory::Create();
+}
+
 void ChromeShellDelegate::Observe(int type,
                                   const content::NotificationSource& source,
                                   const content::NotificationDetails& details) {