Make InstallObserver methods not pure-virtual

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

Index: chrome/browser/ui/app_list/search/app_result.cc
diff --git a/chrome/browser/ui/app_list/search/app_result.cc b/chrome/browser/ui/app_list/search/app_result.cc
index 56e3d88c109bf5a50a1be66ac5213f02ee66f5af..77e9b938c1e9a3d074abd6f7904db9ba0daee797 100644
--- a/chrome/browser/ui/app_list/search/app_result.cc
+++ b/chrome/browser/ui/app_list/search/app_result.cc
@@ -182,22 +182,10 @@ void AppResult::ExtensionEnableFlowAborted(bool user_initiated) {
   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;
@@ -205,10 +193,6 @@ void AppResult::OnExtensionUninstalled(const extensions::Extension* extension) {
   NotifyItemUninstalled();
 }
 
-void AppResult::OnAppsReordered() {}
-
-void AppResult::OnAppInstalledToAppList(const std::string& extension_id) {}
-
 void AppResult::OnShutdown() { StopObservingInstall(); }
 
 }  // namespace app_list