[Packager] Source maps do not seem to work in Chrome

[jtremback]

Getting stacktraces like this:

Error: regeneratorRuntime is not defined
 stack: 
  callee$1$0                                                   index.ios.bundle:1128
  componentDidMount                                            index.ios.bundle:1130
  CallbackQueue.assign.notifyAll                               index.ios.bundle:4916
  ReactNativeReconcileTransaction.ON_DOM_READY_QUEUEING.close  index.ios.bundle:14362
  ReactNativeReconcileTransaction.Mixin.closeAll               index.ios.bundle:6220
  ReactNativeReconcileTransaction.Mixin.perform                index.ios.bundle:6161
  batchedMountComponentIntoNode                                index.ios.bundle:15882
  Object.ReactDefaultBatchingStrategy.batchedUpdates           index.ios.bundle:13951
  Object.batchedUpdates                                        index.ios.bundle:4679
  Object.ReactNativeMount.renderComponent                      index.ios.bundle:15951
  Object.ReactPerf.measure.wrapper [as renderComponent]        index.ios.bundle:5015
  Object.render                                                index.ios.bundle:1310
  renderApplication                                            index.ios.bundle:36269
  Object.AppRegistry.registerComponent.runnables.(anonymous    index.ios.bundle:36171
  Object.AppRegistry.runApplication                            index.ios.bundle:36193
  jsCall                                                       index.ios.bundle:7335
 URL: undefined
 line: undefined
 message: regeneratorRuntime is not defined

However, the redbox on the phone is showing the right source files.