[sync] Bug 1513379 - Only check pending source statuses once. r=bhackett
[sync] Bug 1513379 - Only check pending source statuses once. r=bhackett

darkwing/debugger.html,ruturajv/debugger.html,darkwing/debugger.html,darkwing/debugger.html,darkwing/debugger.html,devtools-html/debugger.html,ruturajv/debugger.html,ruturajv/debugger.html,devtools-html/debugger.html,ruturajv/debugger.html,devtools-html/debugger.html,ruturajv/debugger.html,darkwing/debugger.html,darkwing/debugger.html,devtools-html/debugger.html,devtools-html/debugger.html,devtools-html/debugger.html,ruturajv/debugger.html,darkwing/debugger.html,devtools-html/debugger.html,ruturajv/debugger.html