Make InstallObserver methods not pure-virtual

chrome/browser/ui/app_list/extension_app_model_builder.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_APP_LIST_EXTENSION_APP_MODEL_BUILDER_H_
 #define CHROME_BROWSER_UI_APP_LIST_EXTENSION_APP_MODEL_BUILDER_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 41 matching lines @@
 
   // Builds the model with the current profile.
   void BuildModel();
 
   // extensions::InstallObserver
   virtual void OnBeginExtensionInstall(
       const ExtensionInstallParams& params) OVERRIDE;
   virtual void OnDownloadProgress(const std::string& extension_id,
                                   int percent_downloaded) OVERRIDE;
   virtual void OnInstallFailure(const std::string& extension_id) OVERRIDE;
-  virtual void OnExtensionInstalled(
-      const extensions::Extension* extension) OVERRIDE {}
   virtual void OnExtensionLoaded(
       const extensions::Extension* extension) OVERRIDE;
   virtual void OnExtensionUnloaded(
       const extensions::Extension* extension) OVERRIDE;
   virtual void OnExtensionUninstalled(
       const extensions::Extension* extension) OVERRIDE;
-  virtual void OnAppsReordered() OVERRIDE;
   virtual void OnAppInstalledToAppList(
       const std::string& extension_id) OVERRIDE;
   virtual void OnShutdown() OVERRIDE;
 
   // AppListItemListObserver
   virtual void OnListItemMoved(size_t from_index,
                                size_t to_index,
                                app_list::AppListItem* item) OVERRIDE;
 
   scoped_ptr<ExtensionAppItem> CreateAppItem(
@@ skipping 51 matching lines @@
   // if we try to highlight an app that doesn't exist in the list yet.
   bool highlighted_app_pending_;
 
   // We listen to this to show app installing progress.
   extensions::InstallTracker* tracker_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionAppModelBuilder);
 };
 
 #endif  // CHROME_BROWSER_UI_APP_LIST_EXTENSION_APP_MODEL_BUILDER_H_