Setup an origin trial for HrefTranslate.

In order to setup origin trial need to make the feature & origin trial
dependent on a new runtime enabled feature that is dynamically set if
the translation service is available.

BUG=872777

Change-Id: Ic6fc5947a50c4e2a5ac659c83d75a972c31b0c12
Reviewed-on: https://chromium-review.googlesource.com/c/1332780
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607462}
6 files changed