Implement web speech synthesis.

content/public/browser/tts_dispatcher_host.h

Index: content/public/browser/tts_dispatcher_host.h
diff --git a/content/public/browser/tts_dispatcher_host.h b/content/public/browser/tts_dispatcher_host.h
new file mode 100644
index 0000000000000000000000000000000000000000..c23203a6c15cd4e0842aea79fbb8583bb16992eb
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+++ b/content/public/browser/tts_dispatcher_host.h
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+// 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_PUBLIC_BROWSER_TTS_DISPATCHER_HOST_H_
+#define CONTENT_PUBLIC_BROWSER_TTS_DISPATCHER_HOST_H_
+
+#include "content/common/content_export.h"
+#include "content/public/common/tts_utterance_request.h"
+
+namespace content {
+
+class BrowserContext;
+class TtsDispatcherHost;
+
+class CONTENT_EXPORT TtsDispatcherHostDelegate {
+ public:
+  virtual void OnInitializeVoiceList(TtsDispatcherHost* dispatcher_host) = 0;
+  virtual void OnSpeak(TtsDispatcherHost* dispatcher_host,
+                       const TtsUtteranceRequest& request) = 0;
+  virtual void OnPause(TtsDispatcherHost* dispatcher_host) = 0;
+  virtual void OnResume(TtsDispatcherHost* dispatcher_host) = 0;
+  virtual void OnCancel(TtsDispatcherHost* dispatcher_host) = 0;
+};
+
+class CONTENT_EXPORT TtsDispatcherHost {
+ public:
+  TtsDispatcherHost() {}
+  virtual ~TtsDispatcherHost() {}
+
+  virtual BrowserContext* GetBrowserContext() = 0;
+
+  virtual void DidStartSpeaking(int utterance_id) = 0;
+  virtual void DidFinishSpeaking(int utterance_id) = 0;
+  virtual void DidPauseSpeaking(int utterance_id) = 0;
+  virtual void DidResumeSpeaking(int utterance_id) = 0;
+  virtual void WordBoundary(int utterance_id, int char_index) = 0;
+  virtual void SentenceBoundary(int utterance_id, int char_index) = 0;
+  virtual void MarkerEvent(int utterance_id, int char_index) = 0;
+  virtual void WasInterrupted(int utterance_id) = 0;
+  virtual void WasCancelled(int utterance_id) = 0;
+  virtual void SpeakingErrorOccurred(
+      int utterance_id, const std::string& error_message) = 0;
+  virtual void SendVoiceList(const std::vector<content::TtsVoice>&) = 0;
+
+  DISALLOW_COPY_AND_ASSIGN(TtsDispatcherHost);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_TTS_DISPATCHER_HOST_H_