GitLab

Token fetches by the client may fail for any number of reasons. The
errors should be categorized and returned to //ios/web_view for internal
handling.

Bug: 780937
Change-Id: I84e15d8f43ad8ca1fca8f9be41d82fad0cae6421
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2153337
Commit-Queue: John Wu <jzw@chromium.org>
Reviewed-by: Hiroshi Ichikawa <ichikawa@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759896}