Parameterize PushMessagingBrowserTest to work with bubbles & infobars

chrome/test/data/push_messaging/push_test.js

Index: chrome/test/data/push_messaging/push_test.js
diff --git a/chrome/test/data/push_messaging/push_test.js b/chrome/test/data/push_messaging/push_test.js
index 3412439feace0bfc8db520021f1f768e831a0e57..b47b754a627aa22b677f23f367b7fcac7dad3511 100644
--- a/chrome/test/data/push_messaging/push_test.js
+++ b/chrome/test/data/push_messaging/push_test.js
@@ -6,6 +6,7 @@
 
 var resultQueue = new ResultQueue();
 var pushSubscription = null;
+var lastPermissionRequestResult = '';
 
 var pushSubscriptionOptions = {
   userVisibleOnly: true
@@ -64,10 +65,20 @@ ResultQueue.prototype.popImmediately = function() {
 // this is granted, Push API subscription can succeed.
 function requestNotificationPermission() {
   Notification.requestPermission(function(permission) {
-    sendResultToTest('permission status - ' + permission);
+    lastPermissionRequestResult = permission;

[johnme, 2015/06/02 14:12:38]

What's the purpose of this change? Note that sendResultToTest is already an
asynchronous response mechanism.

Adding timeouts here seems to introduce unnecessary complexity and flakiness.
For example, I notice that 3 of the other patches in
https://code.google.com/p/chromium/issues/detail?id=438758 were reverted due to
flakiness :-o

   });
 }
 
+// The result of requesting permission in requestNotificationPermission() will
+// be sent back. If the permission request has not yet completed, try again
+// after a timeout.
+function getLastPermissionRequestResult(timeout) {
+  if (lastPermissionRequestResult === '')
+    window.setTimeout(getLastPermissionRequestResult, timeout);
+  else
+    sendResultToTest('permission status - ' + lastPermissionRequestResult);
+}
+
 function registerServiceWorker() {
   // The base dir used to resolve service_worker.js and the scope depends on
   // whether this script is included from an html file in ./, subscope1/, or