remove debugging dump() accidentally added in bug 923301

--HG--
extra : transplant_source : %9Bg%E0%7F%CEH%60%E8%23%06%5B%28kMa%BF%A2%84%0A%DC

content/media/webaudio/test/test_delayNodeTailWithDisconnect.html

@@ -45,14 +45,12 @@ function onSourceOutput(e) {
 }
 
 function disconnectSources() {
-  dump("disconnecting\n")
   for (var i = 0; i < sourceCount; ++i) {
     sources[i].disconnect();
   }
 
   SpecialPowers.forceGC();
   SpecialPowers.forceCC();
-  dump("forced GC\n");
 }
 
 function startTest() {