Don't return installed apps in webstore searches in Launcher

chrome/browser/ui/app_list/app_list_controller_delegate.h

Index: chrome/browser/ui/app_list/app_list_controller_delegate.h
diff --git a/chrome/browser/ui/app_list/app_list_controller_delegate.h b/chrome/browser/ui/app_list/app_list_controller_delegate.h
index c654f0eed6fb72e85049ba485a3e4a846be4742b..0fd4a7adc7ec0b9efe41e59b19b7d8a347032a7b 100644
--- a/chrome/browser/ui/app_list/app_list_controller_delegate.h
+++ b/chrome/browser/ui/app_list/app_list_controller_delegate.h
@@ -159,7 +159,8 @@ class AppListControllerDelegate {
       extensions::LaunchType launch_type);
 
   // Returns true if the given extension is installed.
-  bool IsExtensionInstalled(Profile* profile, const std::string& app_id);
+  virtual bool IsExtensionInstalled(Profile* profile,
+                                    const std::string& app_id);
 
   extensions::InstallTracker* GetInstallTrackerFor(Profile* profile);