Bug 862198 - Intermittent browser_net_json-long.js | Test timed out, found a tab, r=rcampbell

browser/devtools/netmonitor/test/browser_net_json-long.js

@@ -11,7 +11,7 @@ function test() {
 
     // This is receiving over 80 KB of json and will populate over 6000 items
     // in a variables view instance. Debug builds are slow.
-    requestLongerTimeout(2);
+    requestLongerTimeout(3);
 
     let { document, L10N, SourceEditor, NetMonitorView } = aMonitor.panelWin;
     let { RequestsMenu } = NetMonitorView;