Stop utterances from a tab when that tab is closed.

chrome/browser/speech/tts_controller.h

Index: chrome/browser/speech/tts_controller.h
diff --git a/chrome/browser/speech/tts_controller.h b/chrome/browser/speech/tts_controller.h
index 45690c941f9f03aa26bb978f4d1a1caa05429925..8f32cd93c152b47125a7bc6751e541088fba41db 100644
--- a/chrome/browser/speech/tts_controller.h
+++ b/chrome/browser/speech/tts_controller.h
@@ -202,10 +202,9 @@ class Utterance {
   }
 
   UtteranceEventDelegate* event_delegate() const {
-    return event_delegate_.get();
+    return event_delegate_;
   }
-  void set_event_delegate(
-      base::WeakPtr<UtteranceEventDelegate> event_delegate) {
+  void set_event_delegate(UtteranceEventDelegate* event_delegate) {
     event_delegate_ = event_delegate;
   }
 
@@ -245,7 +244,7 @@ class Utterance {
   GURL src_url_;
 
   // The delegate to be called when an utterance event is fired.
-  base::WeakPtr<UtteranceEventDelegate> event_delegate_;
+  UtteranceEventDelegate* event_delegate_;
 
   // The parsed options.
   std::string voice_name_;
@@ -315,6 +314,12 @@ class TtsController {
   // Remove delegate that wants to be notified when the set of voices changes.
   virtual void RemoveVoicesChangedDelegate(VoicesChangedDelegate* delegate) = 0;
 
+  // Remove delegate that wants to be notified when an utterance fires an event.
+  // Note: this cancels speech from any utterance with this delegate, and
+  // removes any utterances with this delegate from the queue.
+  virtual void RemoveUtteranceEventDelegate(UtteranceEventDelegate* delegate)
+      = 0;
+
   // Set the delegate that processes TTS requests with user-installed
   // extensions.
   virtual void SetTtsEngineDelegate(TtsEngineDelegate* delegate) = 0;