Removes the dependency to WMTestHelper from app shell.

athena/main/athena_main.cc

Index: athena/main/athena_main.cc
diff --git a/athena/main/athena_main.cc b/athena/main/athena_main.cc
index 692f80d1f10b3e96a2e6898e95a5947a795d83cb..347e9f8baec609ef738410cd416dc9404c8e55fa 100644
--- a/athena/main/athena_main.cc
+++ b/athena/main/athena_main.cc
@@ -19,15 +19,20 @@ class AthenaBrowserMainDelegate : public apps::ShellBrowserMainDelegate {
 
   // apps::ShellBrowserMainDelegate:
   virtual void Start(content::BrowserContext* context) OVERRIDE {
-    athena::StartAthena(apps::ShellDesktopController::instance()
-                            ->GetWindowTreeHost()
-                            ->window());
+    athena::StartAthena(
+        apps::ShellDesktopController::instance()->host()->window());
     CreateTestWindows();
     CreateTestPages(context);
   }
 
   virtual void Shutdown() OVERRIDE { athena::ShutdownAthena(); }
 
+  virtual apps::ShellDesktopController* CreateDesktopController() OVERRIDE {
+    // TODO(mukai): create Athena's own ShellDesktopController subclass so that
+    // it can initialize its own window manager logic.
+    return new apps::ShellDesktopController();
+  }
+
  private:
   DISALLOW_COPY_AND_ASSIGN(AthenaBrowserMainDelegate);
 };