Add UMA to track app launcher discoverability.

chrome/browser/extensions/api/webstore_private/webstore_private_api.cc

Index: chrome/browser/extensions/api/webstore_private/webstore_private_api.cc
diff --git a/chrome/browser/extensions/api/webstore_private/webstore_private_api.cc b/chrome/browser/extensions/api/webstore_private/webstore_private_api.cc
index 95dfcd6c769b49ec1541dc3c8a5bcb12402a7e33..9e541cf978d9cefcd86075351495c0c6fd904ca6 100644
--- a/chrome/browser/extensions/api/webstore_private/webstore_private_api.cc
+++ b/chrome/browser/extensions/api/webstore_private/webstore_private_api.cc
@@ -553,8 +553,10 @@ bool WebstorePrivateCompleteInstallFunction::RunImpl() {
   AppListService* app_list_service =
       AppListService::Get(GetCurrentBrowser()->host_desktop_type());
 
-  if (approval_->enable_launcher)
-    app_list_service->EnableAppList(GetProfile());
+  if (approval_->enable_launcher) {
+    app_list_service->EnableAppList(GetProfile(),
+                                    AppListService::ENABLE_FOR_APP_INSTALL);
+  }
 
   if (IsAppLauncherEnabled() && approval_->manifest->is_app()) {
     // Show the app list to show download is progressing. Don't show the app
@@ -562,7 +564,7 @@ bool WebstorePrivateCompleteInstallFunction::RunImpl() {
     if (approval_->enable_launcher)
       app_list_service->CreateForProfile(GetProfile());
     else
-      app_list_service->ShowForProfile(GetProfile());
+      app_list_service->AutoShowForProfile(GetProfile());
   }
 
   // The extension will install through the normal extension install flow, but
@@ -622,7 +624,7 @@ WebstorePrivateEnableAppLauncherFunction::
 
 bool WebstorePrivateEnableAppLauncherFunction::RunImpl() {
   AppListService::Get(GetCurrentBrowser()->host_desktop_type())->
-      EnableAppList(GetProfile());
+      EnableAppList(GetProfile(), AppListService::ENABLE_VIA_WEBSTORE_LINK);
   return true;
 }