macro/npm: Set CHROME_BIN to chromium-browser

Depends on I0e2224c9 in integration/jenkins.

For projects using karma-chrome-launcher, set CHROME_BIN to Chromium.

By default Karma looks for google-chrome instead of chromium-browser.

Change-Id: I969a8ff360b01bfe93a030e4db8fc7e1bd1069c8