Install emscripten http://lmgtfy.com/?q=install+the+emscripten+sdk

  git clone https://github.com/juj/emsdk.git
  cd emsdk
  ./emsdk install latest
  ./emsdk activate latest
  source ./emsdk_env.sh

Install piexwasm project components

  cd chrome/src/ui/file_manager/image_loader/piex
  npm install

Build piexwasm code: piex.js.wasm piex.out.wasm

  npm run build

Run tests: they must PASS

  npm run test

Release: submit piex.js.wasm piex.out.wasm to the Chromium repository

  git commit -a -m "Release piexwasm ..."
  git cl upload