Output ES6 modules rather than Node
Output ES6 modules rather than Node

This will be useful if we want to run TensorBoard through the Closure Compiler.

PiperOrigin-RevId: 156936819

tensorflow/tensorboard,ioeric/tensorboard,tensorflow/tensorboard,francoisluus/tensorboard-supervise,shakedel/tensorboard,ioeric/tensorboard,qiuminxu/tensorboard,francoisluus/tensorboard-supervise,qiuminxu/tensorboard,ioeric/tensorboard,francoisluus/tensorboard-supervise,shakedel/tensorboard,ioeric/tensorboard,tensorflow/tensorboard,francoisluus/tensorboard-supervise,agrubb/tensorboard,shakedel/tensorboard,ioeric/tensorboard,francoisluus/tensorboard-supervise,agrubb/tensorboard,qiuminxu/tensorboard,shakedel/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard,qiuminxu/tensorboard,agrubb/tensorboard,shakedel/tensorboard,shakedel/tensorboard,agrubb/tensorboard,agrubb/tensorboard,ioeric/tensorboard,qiuminxu/tensorboard,agrubb/tensorboard,tensorflow/tensorboard,francoisluus/tensorboard-supervise,tensorflow/tensorboard,qiuminxu/tensorboard