Move app_shell specific impl from athena_lib to athena_shell_lib

athena/test/sample_activity_factory.h

Index: athena/test/sample_activity_factory.h
diff --git a/athena/test/sample_activity_factory.h b/athena/test/sample_activity_factory.h
index df89a72c97e943ad7b9fa71ac880f4be0c60a080..46d4b94a16954d30a9b00e067ad8a73508bcdc84 100644
--- a/athena/test/sample_activity_factory.h
+++ b/athena/test/sample_activity_factory.h
@@ -21,6 +21,8 @@ class SampleActivityFactory : public ActivityFactory {
                                       const GURL& url) OVERRIDE;
   virtual Activity* CreateAppActivity(
       extensions::ShellAppWindow* app_window) OVERRIDE;
+  virtual Activity* CreateAppActivity(
+      apps::AppWindow* app_window) OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SampleActivityFactory);