Remove unused errorMessage reference

atom/browser/lib/desktop-capturer.js

@@ -59,7 +59,7 @@ desktopCapturer.emit = function(event, name, sources) {
     request = requestsQueue[i];
     if (deepEqual(handledRequest.options, request.options)) {
       if ((ref1 = request.webContents) != null) {
-        ref1.send("ATOM_RENDERER_DESKTOP_CAPTURER_RESULT_" + request.id, errorMessage, result);
+        ref1.send("ATOM_RENDERER_DESKTOP_CAPTURER_RESULT_" + request.id, result);
       }
     } else {
       unhandledRequestsQueue.push(request);

spec/api-desktop-capturer-spec.js

@@ -14,7 +14,7 @@ describe('desktopCapturer', function() {
 
   it('does not throw an error when called twice (regression)', function(done) {
     var callCount = 0;
-    var callback = function(error, sources) {
+    var callback = function (error, sources) {
       callCount++;
       assert.equal(error, null);
       assert.notEqual(sources.length, 0);