Get rid of src_extension_id from TtsController.

chrome/browser/speech/extension_api/tts_extension_api.cc

Index: chrome/browser/speech/extension_api/tts_extension_api.cc
diff --git a/chrome/browser/speech/extension_api/tts_extension_api.cc b/chrome/browser/speech/extension_api/tts_extension_api.cc
index 823b849d36723c895d1f3e3d87e2ec45a15345c8..f2837efe59ca93357fdaaacdf515f481e8a10305 100644
--- a/chrome/browser/speech/extension_api/tts_extension_api.cc
+++ b/chrome/browser/speech/extension_api/tts_extension_api.cc
@@ -86,12 +86,24 @@ class TtsExtensionEventHandler
     : public UtteranceEventDelegate,
       public base::SupportsWeakPtr<TtsExtensionEventHandler> {
  public:
+  explicit TtsExtensionEventHandler(const std::string& src_extension_id);
+
   virtual void OnTtsEvent(Utterance* utterance,
                           TtsEventType event_type,
                           int char_index,
                           const std::string& error_message) override;
+
+ private:
+  // The extension ID of the extension that called speak() and should
+  // receive events.
+  std::string src_extension_id_;
 };
 
+TtsExtensionEventHandler::TtsExtensionEventHandler(
+    const std::string& src_extension_id)
+    : src_extension_id_(src_extension_id) {
+}
+
 void TtsExtensionEventHandler::OnTtsEvent(Utterance* utterance,
                                           TtsEventType event_type,
                                           int char_index,
@@ -130,7 +142,7 @@ void TtsExtensionEventHandler::OnTtsEvent(Utterance* utterance,
   event->restrict_to_browser_context = utterance->browser_context();
   event->event_url = utterance->src_url();
   extensions::EventRouter::Get(utterance->browser_context())
-      ->DispatchEventToExtension(utterance->src_extension_id(), event.Pass());
+      ->DispatchEventToExtension(src_extension_id_, event.Pass());
 
   if (utterance->finished())
     delete this;
@@ -267,7 +279,6 @@ bool TtsSpeakFunction::RunAsync() {
   Utterance* utterance = new Utterance(GetProfile());
   utterance->set_text(text);
   utterance->set_voice_name(voice_name);
-  utterance->set_src_extension_id(extension_id());
   utterance->set_src_id(src_id);
   utterance->set_src_url(source_url());
   utterance->set_lang(lang);
@@ -279,7 +290,7 @@ bool TtsSpeakFunction::RunAsync() {
   utterance->set_extension_id(voice_extension_id);
   utterance->set_options(options.get());
   utterance->set_event_delegate(
-      (new TtsExtensionEventHandler())->AsWeakPtr());
+      (new TtsExtensionEventHandler(extension_id()))->AsWeakPtr());
 
   TtsController* controller = TtsController::GetInstance();
   controller->SpeakOrEnqueue(utterance);