Example of usage of new features of context and screen.

chrome/browser/ui/webui/chromeos/login/controller_pairing_screen_handler.h

Index: chrome/browser/ui/webui/chromeos/login/controller_pairing_screen_handler.h
diff --git a/chrome/browser/ui/webui/chromeos/login/controller_pairing_screen_handler.h b/chrome/browser/ui/webui/chromeos/login/controller_pairing_screen_handler.h
new file mode 100644
index 0000000000000000000000000000000000000000..8a4743a2c66b7b2273031badc014f15bd917dfa6
--- /dev/null
+++ b/chrome/browser/ui/webui/chromeos/login/controller_pairing_screen_handler.h
@@ -0,0 +1,47 @@
+// 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 CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_CONTROLLER_PAIRING_SCREEN_HANDLER_H_
+#define CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_CONTROLLER_PAIRING_SCREEN_HANDLER_H_
+
+#include "base/macros.h"
+#include "chrome/browser/chromeos/login/screens/controller_pairing_screen_actor.h"
+#include "chrome/browser/ui/webui/chromeos/login/base_screen_handler.h"
+
+namespace chromeos {
+
+class ControllerPairingScreenHandler : public ControllerPairingScreenActor,
+                                       public BaseScreenHandler {
+ public:
+  ControllerPairingScreenHandler();
+  virtual ~ControllerPairingScreenHandler();
+
+ private:
+  void HandleButtonClicked(const std::string& action);
+  void HandleContextChanged(const base::DictionaryValue* diff);
+  void HandleAuthenticated(const std::string& user_id);
+
+  // Overridden from BaseScreenHandler:
+  virtual void Initialize() OVERRIDE;
+  virtual void DeclareLocalizedValues(LocalizedValuesBuilder* builder) OVERRIDE;
+
+  // Overridden from content::WebUIMessageHandler:
+  virtual void RegisterMessages() OVERRIDE;
+
+  // Overridden from ControllerPairingScreenActor:
+  virtual void Show() OVERRIDE;
+  virtual void Hide() OVERRIDE;
+  virtual void SetDelegate(Delegate* delegate) OVERRIDE;
+  virtual void OnContextChanged(const base::DictionaryValue& diff) OVERRIDE;
+  virtual content::BrowserContext* GetBrowserContext() OVERRIDE;
+
+  ControllerPairingScreenActor::Delegate* delegate_;
+  bool show_on_init_;
+
+  DISALLOW_COPY_AND_ASSIGN(ControllerPairingScreenHandler);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_UI_WEBUI_CHROMEOS_LOGIN_CONTROLLER_PAIRING_SCREEN_HANDLER_H_