Make InstallObserver methods not pure-virtual

chrome/browser/ui/app_list/search/app_result.cc

 // 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.
 
 #include "chrome/browser/ui/app_list/search/app_result.h"
 
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_util.h"
 #include "chrome/browser/extensions/install_tracker.h"
 #include "chrome/browser/extensions/install_tracker_factory.h"
@@ skipping 164 matching lines @@
 
   // Automatically open app after enabling.
   Open(ui::EF_NONE);
 }
 
 void AppResult::ExtensionEnableFlowAborted(bool user_initiated) {
   extension_enable_flow_.reset();
   controller_->OnCloseExtensionPrompt();
 }
 
-void AppResult::OnBeginExtensionInstall(
-    const ExtensionInstallParams& params) {}
-
-void AppResult::OnDownloadProgress(const std::string& extension_id,
-                                   int percent_downloaded) {}
-
-void AppResult::OnInstallFailure(const std::string& extension_id) {}
-
-void AppResult::OnExtensionInstalled(const extensions::Extension* extension) {}
-
 void AppResult::OnExtensionLoaded(const extensions::Extension* extension) {
   UpdateIcon();
 }
 
-void AppResult::OnExtensionUnloaded(const extensions::Extension* extension) {}
-
 void AppResult::OnExtensionUninstalled(const extensions::Extension* extension) {
   if (extension->id() != app_id_)
     return;
 
   NotifyItemUninstalled();
 }
 
-void AppResult::OnAppsReordered() {}
-
-void AppResult::OnAppInstalledToAppList(const std::string& extension_id) {}
-
 void AppResult::OnShutdown() { StopObservingInstall(); }
 
 }  // namespace app_list