Bug 1320994 - Increase retries for screensharing preview window. r=florian

MozReview-Commit-ID: IPnLWPT8SNP

--HG--
extra : rebase_source : 21b082ae29fed7332ecafcd500d6cb8e25e42217

browser/base/content/test/webrtc/browser_devices_get_user_media_screen.js

@@ -55,7 +55,7 @@ var gTests = [
     menulist.getItemAtIndex(2).doCommand();
     ok(!document.getElementById("webRTC-all-windows-shared").hidden,
        "the 'all windows will be shared' warning should now be visible");
-    yield promiseWaitForCondition(() => !document.getElementById("webRTC-preview").hidden);
+    yield promiseWaitForCondition(() => !document.getElementById("webRTC-preview").hidden, 100);
     ok(!document.getElementById("webRTC-preview").hidden,
        "the preview area is visible");
     ok(!document.getElementById("webRTC-previewWarning").hidden,

browser/base/content/test/webrtc/head.js

@@ -30,9 +30,9 @@ function waitForCondition(condition, nextTest, errorMsg, retryTimes) {
   var moveOn = function() { clearInterval(interval); nextTest(); };
 }
 
-function promiseWaitForCondition(aConditionFn) {
+function promiseWaitForCondition(aConditionFn, retryTimes) {
   let deferred = Promise.defer();
-  waitForCondition(aConditionFn, deferred.resolve, "Condition didn't pass.");
+  waitForCondition(aConditionFn, deferred.resolve, "Condition didn't pass.", retryTimes);
   return deferred.promise;
 }