Delete the old hotwording integration.

chrome/browser/ui/webui/app_list/start_page_handler.h

 // Copyright 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 CHROME_BROWSER_UI_WEBUI_APP_LIST_START_PAGE_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_APP_LIST_START_PAGE_HANDLER_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/prefs/pref_change_registrar.h"
-#include "base/scoped_observer.h"
 #include "content/public/browser/web_ui_message_handler.h"
-#include "extensions/browser/extension_registry_observer.h"
 
 namespace base {
 class ListValue;
 }
 
 namespace extensions {
 class ExtensionRegistry;
 }
 
 namespace app_list {
 
 // Handler for the app launcher start page.
-class StartPageHandler : public content::WebUIMessageHandler,
-                         public extensions::ExtensionRegistryObserver {
+class StartPageHandler : public content::WebUIMessageHandler {
  public:
   StartPageHandler();
   ~StartPageHandler() override;
 
  private:
   // content::WebUIMessageHandler overrides:
   void RegisterMessages() override;
 
-  // extensions::ExtensionRegistryObserver implementation.
-  void OnExtensionLoaded(content::BrowserContext* browser_context,
-                         const extensions::Extension* extension) override;
-  void OnExtensionUnloaded(
-      content::BrowserContext* browser_context,
-      const extensions::Extension* extension,
-      extensions::UnloadedExtensionInfo::Reason reason) override;
-
-#if defined(OS_CHROMEOS)
-  // Called when the pref has been changed.
-  void OnHotwordEnabledChanged();
-#endif
-
   // JS callbacks.
   void HandleAppListShown(const base::ListValue* args);
   void HandleDoodleClicked(const base::ListValue* args);
   void HandleInitialize(const base::ListValue* args);
   void HandleLaunchApp(const base::ListValue* args);
-  void HandleSpeechResult(const base::ListValue* args);
-  void HandleSpeechSoundLevel(const base::ListValue* args);
-  void HandleSpeechRecognition(const base::ListValue* args);
 
   PrefChangeRegistrar pref_change_registrar_;
 
-  ScopedObserver<extensions::ExtensionRegistry,
-                 extensions::ExtensionRegistryObserver>
-      extension_registry_observer_;
-
   DISALLOW_COPY_AND_ASSIGN(StartPageHandler);
 };
 
 }  // namespace app_list
 
 #endif  // CHROME_BROWSER_UI_WEBUI_APP_LIST_START_PAGE_HANDLER_H_