Bug 1303380 - Wrap the telemetry code in _firstWindowLoaded with a try/catch to allow startup and migration code to run to completion if there is an exception writing to Telemetry. r=Gijs

MozReview-Commit-ID: DPfq6lZ4fM3

--HG--
extra : rebase_source : 072713f1bf4dc30b681e57660b740a137e8ee7aa

browser/components/nsBrowserGlue.js

@@ -931,7 +931,9 @@ BrowserGlue.prototype = {
     }
     if (SCALING_PROBE_NAME) {
       let scaling = aWindow.devicePixelRatio * 100;
-      Services.telemetry.getHistogramById(SCALING_PROBE_NAME).add(scaling);
+      try {
+        Services.telemetry.getHistogramById(SCALING_PROBE_NAME).add(scaling);
+      } catch (ex) {}
     }
   },