Stop utterances from a tab when that tab is closed.

chrome/browser/speech/extension_api/tts_extension_api.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/speech/extension_api/tts_extension_api.h"
 
 #include <string>
 
 #include "base/lazy_instance.h"
-#include "base/memory/weak_ptr.h"
 #include "base/values.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/speech/extension_api/tts_engine_extension_api.h"
 #include "chrome/browser/speech/extension_api/tts_engine_extension_observer.h"
 #include "chrome/browser/speech/extension_api/tts_extension_api_constants.h"
 #include "chrome/browser/speech/tts_controller.h"
 #include "extensions/browser/event_router.h"
 #include "extensions/browser/extension_function_registry.h"
 #include "ui/base/l10n/l10n_util.h"
 
@@ skipping 55 matching lines @@
 
   NOTREACHED();
   return TTS_EVENT_ERROR;
 }
 
 namespace extensions {
 
 // One of these is constructed for each utterance, and deleted
 // when the utterance gets any final event.
 class TtsExtensionEventHandler
-    : public UtteranceEventDelegate,
-      public base::SupportsWeakPtr<TtsExtensionEventHandler> {
+    : public UtteranceEventDelegate {
  public:
   explicit TtsExtensionEventHandler(const std::string& src_extension_id);
 
   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
@@ skipping 184 matching lines @@
   utterance->set_src_id(src_id);
   utterance->set_src_url(source_url());
   utterance->set_lang(lang);
   utterance->set_gender(gender);
   utterance->set_continuous_parameters(continuous_params);
   utterance->set_can_enqueue(can_enqueue);
   utterance->set_required_event_types(required_event_types);
   utterance->set_desired_event_types(desired_event_types);
   utterance->set_extension_id(voice_extension_id);
   utterance->set_options(options.get());
-  utterance->set_event_delegate(
-      (new TtsExtensionEventHandler(extension_id()))->AsWeakPtr());
+  utterance->set_event_delegate(new TtsExtensionEventHandler(extension_id()));
 
   TtsController* controller = TtsController::GetInstance();
   controller->SpeakOrEnqueue(utterance);
   return true;
 }
 
 bool TtsStopSpeakingFunction::RunSync() {
   TtsController::GetInstance()->Stop();
   return true;
 }
@@ skipping 67 matching lines @@
 }
 
 static base::LazyInstance<BrowserContextKeyedAPIFactory<TtsAPI> > g_factory =
     LAZY_INSTANCE_INITIALIZER;
 
 BrowserContextKeyedAPIFactory<TtsAPI>* TtsAPI::GetFactoryInstance() {
   return g_factory.Pointer();
 }
 
 }  // namespace extensions