commit d20e8f05588bdcc60a94d91f767a08c9bb44fc92
author reillyg <reillyg@chromium.org> Tue Mar 01 22:19:51 2016
committer Commit bot <commit-bot@chromium.org> Tue Mar 01 22:22:19 2016
tree 7bbfa146d37c278e0384d80bf732e26c11ee1bc4
parent c6688e12756110ff918cac35584ffca59e2023cb

Basic layout tests for WebUSB.

This change relands https://codereview.chromium.org/1734753003/ with
additional layout tests that provide basic coverage of all the functions
defined by the WebUSB API. The tests are implemented by providing mock
implementations of the Mojo services that Blink depends on to provide
the WebUSB API, allowing the entire test implementation to be done in
Javascript.

Discovered a number of bugs in isochronous packet handling while writing
these.

BUG=492204

Review URL: https://codereview.chromium.org/1730403006

Cr-Commit-Position: refs/heads/master@{#378578}