Implement web speech synthesis.

chrome/browser/speech/tts_message_filter.h

+// Copyright (c) 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 CHROME_BROWSER_SPEECH_TTS_MESSAGE_FILTER_H_
+#define CHROME_BROWSER_SPEECH_TTS_MESSAGE_FILTER_H_
+
+#include "chrome/browser/speech/tts_controller.h"
+#include "chrome/common/tts_messages.h"
+#include "content/public/browser/browser_message_filter.h"
+
+class Profile;
+
+class TtsMessageFilter
+    : public content::BrowserMessageFilter,
+      public UtteranceEventDelegate {
+ public:
+  TtsMessageFilter(int render_process_id, Profile* profile);
+
+  // content::BrowserMessageFilter implementation.
+  virtual void OverrideThreadForMessage(
+      const IPC::Message& message,
+      content::BrowserThread::ID* thread) OVERRIDE;
+  virtual bool OnMessageReceived(const IPC::Message& message,
+                                 bool* message_was_ok) OVERRIDE;
+
+  // UtteranceEventDelegate implementation.
+  virtual void OnTtsEvent(Utterance* utterance,
+                          TtsEventType event_type,
+                          int char_index,
+                          const std::string& error_message) OVERRIDE;
+
+ private:
+  virtual ~TtsMessageFilter();
+
+  void OnInitializeVoiceList();
+  void OnSpeak(const TtsUtteranceRequest& utterance);
+  void OnPause();
+  void OnResume();
+  void OnCancel();
+
+  int render_process_id_;
+  Profile* profile_;
+
+  DISALLOW_COPY_AND_ASSIGN(TtsMessageFilter);
+};
+
+#endif  // CHROME_BROWSER_SPEECH_TTS_MESSAGE_FILTER_H_