Introduces the speech recognition UI to app_list.

ui/app_list/speech_ui_model_observer.h

+// Copyright 2013 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 UI_APP_LIST_SPEECH_UI_MODEL_OBSERVER_H_
+#define UI_APP_LIST_SPEECH_UI_MODEL_OBSERVER_H_
+
+#include "base/basictypes.h"
+#include "base/strings/string16.h"
+#include "ui/app_list/app_list_export.h"
+
+namespace app_list {
+
+enum SpeechRecognitionState {
+  SPEECH_RECOGNITION_NOT_STARTED = 0,
+  SPEECH_RECOGNITION_ON,
+  SPEECH_RECOGNITION_IN_SPEECH,
+};
+
+class APP_LIST_EXPORT SpeechUIModelObserver {
+ public:
+  // Invoked when sound level for the speech recognition has changed.
+  virtual void OnSpeechSoundLevelChanged(int16 level) {}
+
+  // Invoked when a speech result arrives. |is_final| is true only when the
+  // speech result is final.
+  virtual void OnSpeechResult(const base::string16& result, bool is_final) {}
+
+  // Invoked when the state of speech recognition is changed.
+  virtual void OnSpeechRecognitionStateChanged(
+      SpeechRecognitionState new_state) {}
+
+ protected:
+  virtual ~SpeechUIModelObserver() {}
+};
+
+}  // namespace app_list
+
+#endif  // UI_APP_LIST_SPEECH_UI_MODEL_OBSERVER_H_