[win] Add a progress bar in the app launcher for app installs.

chrome/browser/ui/cocoa/app_list/app_list_controller_cocoa.mm

Index: chrome/browser/ui/cocoa/app_list/app_list_controller_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/app_list/app_list_controller_cocoa.mm b/chrome/browser/ui/cocoa/app_list/app_list_controller_cocoa.mm
index 61dd01e8b773a8e87996c22b2923508d0905af38..3580de6ee685fb2e675a29ea5898bf937d063986 100644
--- a/chrome/browser/ui/cocoa/app_list/app_list_controller_cocoa.mm
+++ b/chrome/browser/ui/cocoa/app_list/app_list_controller_cocoa.mm
@@ -87,4 +87,10 @@ void NotifyAppListOfBeginExtensionInstall(
     const gfx::ImageSkia& installing_icon) {
 }
 
+void NotifyAppListOfDownloadProgress(
+    Profile* profile,
+    const std::string& extension_id,
+    int percent_downloaded) {
+}
+
 }  // namespace chrome