Make 'auto' invalid for the 'hyphens' property when no dictionaries

This patch makes the 'auto' value invalid for the 'hyphens' property on
platforms that do not support, as discussed in blink-dev[1].

[1] https://groups.google.com/a/chromium.org/d/msg/blink-dev/LsnvY7FFrY0/XfAcOFYYAAAJ

BUG=605840

Review-Url: https://codereview.chromium.org/2342433002
Cr-Commit-Position: refs/heads/master@{#418900}
4 files changed