Bug 1300658 P3 Don't fail test_consoleAndBlobs.html if other console messages are received. r=baku

dom/workers/test/test_consoleAndBlobs.html

@@ -22,12 +22,14 @@
     observe: function(aSubject, aTopic, aData) {
       ok(true, "Something has been received");
       is(aTopic, "console-api-log-event");
-      SpecialPowers.removeObserver(this, "console-api-log-event");
 
       var obj = aSubject.wrappedJSObject;
-      is(obj.arguments[0].size, 3, "The size is correct");
-      is(obj.arguments[0].type, 'foo/bar', "The type is correct");
-      SimpleTest.finish();
+      if (obj.arguments[0] && obj.arguments[0].msg === 'consoleAndBlobs') {
+        SpecialPowers.removeObserver(this, "console-api-log-event");
+        is(obj.arguments[0].blob.size, 3, "The size is correct");
+        is(obj.arguments[0].blob.type, 'foo/bar', "The type is correct");
+        SimpleTest.finish();
+      }
     }
   }
 

dom/workers/test/worker_consoleAndBlobs.js

@@ -5,4 +5,4 @@
 "use strict";
 
 var b = new Blob(['123'], { type: 'foo/bar'});
-console.log(b);
+console.log({ msg: 'consoleAndBlobs', blob: b });