Convert Oscillator Audit tests to testharness

third_party/WebKit/LayoutTests/webaudio/resources/late-start-testing.js

 function runLateStartTest(audit, context, node) {
 
   // Set up a dummy signal path to keep the audio context running and spend
   // processing time before calling start(0).
   var osc = context.createOscillator();
   var silent = context.createGain();
 
   osc.connect(silent);
   silent.connect(context.destination);
   silent.gain.setValueAtTime(0.0, 0);
@@ skipping 25 matching lines @@
       }
 
       var success =
           Should('The index of first non-zero value',nonZeroValueIndex)
               .notBeEqualTo(-1);
       success = Should('The first sample value', channelData[0])
           .beEqualTo(0) && success;
       Should('The rendered buffer', success)
           .summarize('contains non-zero values after the first sample',
                      'was all zeros or has non-zero first sample.');
-
       done();
     });
   });
 
-  audit.defineTask('finish-test', function (done) {
-    done();
-    finishJSTest();
-  });
-
-  audit.runTasks(
-    'test-late-start',
-    'finish-test'
-  );
-
+  audit.runTasks();
 }