Add a specialized apps::NativeAppWindow for app_shell

apps/shell/browser/shell_apps_client.h

Index: apps/shell/browser/shell_apps_client.h
diff --git a/apps/shell/browser/shell_apps_client.h b/apps/shell/browser/shell_apps_client.h
new file mode 100644
index 0000000000000000000000000000000000000000..c9db4f0901458c51699d8d0c6b39c621359e31f7
--- /dev/null
+++ b/apps/shell/browser/shell_apps_client.h
@@ -0,0 +1,44 @@
+// 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 APPS_SHELL_BROWSER_SHELL_APPS_CLIENT_H_
+#define APPS_SHELL_BROWSER_SHELL_APPS_CLIENT_H_
+
+#include "apps/apps_client.h"
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+
+namespace content {
+class BrowserContext;
+}
+
+namespace apps {
+
+// The implementation of AppsClient for app_shell.
+class ShellAppsClient : public AppsClient {
+ public:
+  // For app_shell only a single browser context is supported.
+  explicit ShellAppsClient(content::BrowserContext* browser_context);
+  virtual ~ShellAppsClient();
+
+ private:
+  // apps::AppsClient implementation:
+  virtual std::vector<content::BrowserContext*> GetLoadedBrowserContexts()
+      OVERRIDE;
+  virtual bool CheckAppLaunch(content::BrowserContext* context,
+                              const extensions::Extension* extension) OVERRIDE;
+  virtual ShellWindow* CreateShellWindow(content::BrowserContext* context,
+                                         const extensions::Extension* extension)
+      OVERRIDE;
+  virtual void StartKeepAlive() OVERRIDE;
+  virtual void EndKeepAlive() OVERRIDE;
+
+  content::BrowserContext* browser_context_;
+
+  DISALLOW_COPY_AND_ASSIGN(ShellAppsClient);
+};
+
+}  // namespace apps
+
+#endif  // APPS_SHELL_BROWSER_SHELL_APPS_CLIENT_H_