code: function closeChromium(done) {
              var child = self.process;
  
              // remove error handlers
              if (child) {
                  child.removeListener('error', handlers.relayError);
                  child.removeListener('exit', handlers.prematureExit);
                  child.stderr.removeListener('error', handlers.relayError);
                  child.stdout.removeListener('error', handlers.relayError);
              }
  
              // kill chromium
              if (isKilled(child) === false) {
                  // make sure stdout & stderr isn't paused, since the child won't
                  // emit 'close' until the file descriptors are destroyed
                  child.stdout.resume();
                  child.stderr.resume();
                  child.once('close', done);
                  child.kill();
              } else {
                  done(null);
              }
          }
docs: if browser is alive, kill it