Add fromPixels test (#1794)
Add fromPixels test (#1794)

INTERNAL

tensorflow/tfjs,tensorflow/tfjs-core,tensorflow/tfjs,tensorflow/tfjs,tensorflow/tfjs-core,tensorflow/tfjs-core,tensorflow/tfjs-core,tensorflow/tfjs,tensorflow/tfjs,tensorflow/tfjs-core,tensorflow/tfjs-core,tensorflow/tfjs,tensorflow/tfjs,tensorflow/tfjs,tensorflow/tfjs