anchor.diff:      String driverContent = """
   <!DOCTYPE html><html>
   <head>
  +  <style>
  +    body {
  +      margin: 0;
  +    }
  +    .box {
  +      overflow: hidden;
  +      overflow-y: auto;
  +      position: absolute;
  +      left: 0;
  +      right: 0;
  +    }
  +    .controller.box {
  +      height: 75px;
  +      top: 0;
  +    }
  +    .test.box {
  +      top: 75px;
  +      bottom: 0;
  +    }
  +  </style>
     <title>Driving page</title>
     <script type='text/javascript'>
       var STATUS_UPDATE_INTERVAL = 10000;
  
positive.code:   </script>
  </head>
    <body onload="startTesting()">
      Dart test driver, number of tests: <div id="number"></div><br>
      Currently executing: <div id="currently_executing"></div><br>
      Unhandled error: <div id="unhandled_error"></div>
      <iframe id="embedded_iframe"></iframe>
    </body>
  </html>
  """;
  
negative.code:   }
  
    Future<bool> terminate() {
      var browsers = [];
      underTermination = true;
      testingServer.underTermination = true;
      for (BrowserTestingStatus status in browserStatus.values) {
        browsers.add(status.browser);
        if (status.nextTestTimeout != null) {
          status.nextTestTimeout.cancel();
          status.nextTestTimeout = null;
        }
      }
      // Success if all the browsers closed successfully.
      bool success = true;
      Future closeBrowser(Browser b) {
        return b.close().then((bool closeSucceeded) {
          if (!closeSucceeded) {
            success = false;
          }
        });
      }
      return Future.forEach(browsers, closeBrowser).then((_) {
        testingServer.errorReportingServer.close();
        printDoubleReportingTests();
        return success;
      });
    }
  
  