Decompose BrowserStateMonitor into two parts, simplifying unit tests and APIs.

chrome/browser/chromeos/input_method/input_method_persistence.h

+// Copyright (c) 2012 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_CHROMEOS_INPUT_METHOD_INPUT_METHOD_PERSISTENCE_H_
+#define CHROME_BROWSER_CHROMEOS_INPUT_METHOD_INPUT_METHOD_PERSISTENCE_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "chrome/browser/chromeos/input_method/input_method_manager.h"
+
+namespace chromeos {
+namespace input_method {
+
+// Observes input method and session state changes, and persists input method
+// changes to the BrowserProcess local state or to the user preferences,
+// according to the session state.
+class InputMethodPersistence : public InputMethodManager::Observer {
+ public:
+  // Constructs an instance that will observe input method changes on the
+  // provided InputMethodManager. The client is responsible for calling
+  // OnSessionStateChange whenever the InputMethodManager::State changes.
+  explicit InputMethodPersistence(InputMethodManager* input_method_manager);
+  virtual ~InputMethodPersistence();
+
+  // Receives notification of session state changes.
+  void OnSessionStateChange(InputMethodManager::State new_state);
+
+  // InputMethodManager::Observer overrides.
+  virtual void InputMethodChanged(InputMethodManager* manager,
+                                  bool show_message) OVERRIDE;
+  virtual void InputMethodPropertyChanged(InputMethodManager* manager) OVERRIDE;
+
+ private:
+  InputMethodManager* input_method_manager_;
+  InputMethodManager::State state_;
+  DISALLOW_COPY_AND_ASSIGN(InputMethodPersistence);
+};
+
+}  // namespace input_method
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_INPUT_METHOD_INPUT_METHOD_PERSISTENCE_H_