Implement web speech synthesis.

content/browser/speech/tts_dispatcher_host_impl.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 CONTENT_BROWSER_SPEECH_TTS_DISPATCHER_HOST_IMPL_H_
+#define CONTENT_BROWSER_SPEECH_TTS_DISPATCHER_HOST_IMPL_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "content/common/content_export.h"
+#include "content/common/tts_messages.h"
+#include "content/public/browser/browser_message_filter.h"
+#include "content/public/browser/tts_dispatcher_host.h"
+
+namespace content {
+
+// TtsDispatcherHost is a delegate for Speech API messages used by
+// RenderMessageFilter.
+class CONTENT_EXPORT TtsDispatcherHostImpl
+    : public BrowserMessageFilter,
+      public TtsDispatcherHost {
+ public:
+  TtsDispatcherHostImpl(int render_process_id,
+                        BrowserContext* browser_context);
+
+  virtual BrowserContext* GetBrowserContext() OVERRIDE;
+
+  // TtsDispatcherHost methods.
+  virtual void DidStartSpeaking(int utterance_id) OVERRIDE;
+  virtual void DidFinishSpeaking(int utterance_id) OVERRIDE;
+  virtual void DidPauseSpeaking(int utterance_id) OVERRIDE;
+  virtual void DidResumeSpeaking(int utterance_id) OVERRIDE;
+  virtual void WordBoundary(int utterance_id, int char_index) OVERRIDE;
+  virtual void SentenceBoundary(
+      int utterance_id, int char_index) OVERRIDE;
+  virtual void MarkerEvent(int utterance_id, int char_index) OVERRIDE;
+  virtual void WasInterrupted(int utterance_id) OVERRIDE;
+  virtual void WasCancelled(int utterance_id) OVERRIDE;
+  virtual void SpeakingErrorOccurred(
+      int utterance_id, const std::string& error_message) OVERRIDE;
+  virtual void SendVoiceList(const std::vector<content::TtsVoice>&) OVERRIDE;
+
+  // BrowserMessageFilter implementation.
+  virtual bool OnMessageReceived(const IPC::Message& message,
+                                 bool* message_was_ok) OVERRIDE;
+
+ private:
+  virtual ~TtsDispatcherHostImpl();
+
+  void OnInitializeVoiceList();
+  void OnSpeak(const TtsUtteranceRequest& utterance);
+  void OnPause();
+  void OnResume();
+  void OnCancel();
+
+  int render_process_id_;
+  BrowserContext* browser_context_;
+  TtsDispatcherHostDelegate* delegate_;
+
+  DISALLOW_COPY_AND_ASSIGN(TtsDispatcherHostImpl);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_SPEECH_TTS_DISPATCHER_HOST_IMPL_H_