From d96579c768b53d98814d62d31058816537e874d8 Mon Sep 17 00:00:00 2001
From: Rob Wu <rob@robwu.nl>
Date: Sun, 7 Aug 2016 19:09:03 -0700
Subject: [PATCH] Bug 1288276 - Add chromeScript.awaitOneMessage to
 SpecialPowers r=billm

MozReview-Commit-ID: DcqnN3TosM8

--HG--
extra : rebase_source : 578e6437ef32830fdd3a1081947ca8081d1e3497
---
 testing/specialpowers/content/specialpowersAPI.js | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/testing/specialpowers/content/specialpowersAPI.js b/testing/specialpowers/content/specialpowersAPI.js
index ee3e43c92979..f7e84bff74d3 100644
--- a/testing/specialpowers/content/specialpowersAPI.js
+++ b/testing/specialpowers/content/specialpowersAPI.js
@@ -503,6 +503,13 @@ SpecialPowersAPI.prototype = {
         listeners.push({ name: name, listener: listener });
       },
 
+      promiseOneMessage: name => new Promise(resolve => {
+        chromeScript.addMessageListener(name, function listener(message) {
+          chromeScript.removeMessageListener(name, listener);
+          resolve(message);
+        });
+      }),
+
       removeMessageListener: (name, listener) => {
         listeners = listeners.filter(
           o => (o.name != name || o.listener != listener)