Better configure the Chrome launcher.
Better configure the Chrome launcher.

This uses the right executables on OS X and Windows, and passes flags
to disable even more features.

R=kevmoo@google.com

Review URL: https://codereview.chromium.org//978093003

apwilson/test,kevmoo/test,d2m/test,greglittlefield-wf/test,kevmoo/test,greglittlefield-wf/test,greglittlefield-wf/test,apwilson/test,iglherme/Guttiest,grouma/test,kevmoo/test,d2m/test,apwilson/test,iglherme/Guttiest,grouma/test,iglherme/Guttiest,d2m/test,grouma/test