Move app_shell specific impl from athena_lib to athena_shell_lib

athena/content/shell/shell_app_activity.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef ATHENA_CONTENT_SHELL_SHELL_APP_ACTIVITY_H_
+#define ATHENA_CONTENT_SHELL_SHELL_APP_ACTIVITY_H_
+
+#include "athena/content/app_activity.h"
+
+#include "base/memory/scoped_ptr.h"
+
+namespace extensions {
+class ShellAppWindow;
+}
+
+namespace athena {
+
+class ShellAppActivity : public AppActivity {
+ public:
+  explicit ShellAppActivity(extensions::ShellAppWindow* app_window);
+  virtual ~ShellAppActivity();
+
+ private:
+  // AppActivity:
+  virtual content::WebContents* GetWebContents() OVERRIDE;
+
+  scoped_ptr<extensions::ShellAppWindow> shell_app_window_;
+
+  DISALLOW_COPY_AND_ASSIGN(ShellAppActivity);
+};
+
+}  // namespace athena
+
+#endif  // ATHENA_CONTENT_SHELL_SHELL_APP_ACTIVITY_H_