Support app.window.create on athena

extensions/shell/browser/shell_browser_main_delegate.h

Index: extensions/shell/browser/shell_browser_main_delegate.h
diff --git a/extensions/shell/browser/shell_browser_main_delegate.h b/extensions/shell/browser/shell_browser_main_delegate.h
index 1b234c514d3c131a6f8a3485d66b6ea5a6cf08f2..fb1092f0e40254330c858b5fb373956ac6366eed 100644
--- a/extensions/shell/browser/shell_browser_main_delegate.h
+++ b/extensions/shell/browser/shell_browser_main_delegate.h
@@ -11,6 +11,7 @@ class BrowserContext;
 
 namespace extensions {
 
+class AppsClient;
 class DesktopController;
 
 class ShellBrowserMainDelegate {
@@ -29,6 +30,9 @@ class ShellBrowserMainDelegate {
   // and window manager. Subclass may return its subclass to customize the
   // windo manager.
   virtual DesktopController* CreateDesktopController() = 0;
+
+  // Creates the AppsClient instance to support app.window extension API.
+  virtual AppsClient* CreateAppsClient() = 0;
 };
 
 }  // namespace extensions