Add WPT Serve to serve the content of tests.

Fix WPT WebDriver test failures due to the lack of WPT Serve to serve the test content.
Add a flag to Chrome to reroute web-platform.test to 127.0.0.1

No-Export: True
Bug: 881513
Change-Id: I34398bc0eb7b3d8e288aae4358d2b195b46c324a
Reviewed-on: https://chromium-review.googlesource.com/c/1462139
Reviewed-by: John Chen <johnchen@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Kyle Ju <kyleju@chromium.org>
Cr-Commit-Position: refs/heads/master@{#632623}
3 files changed