GitLab

Added comment and set linux-rel as 100% experimental
in the new config group.

Bug: 922150
Change-Id: I67e85580e8a43567d2189ee1cbaf578769065b8b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1769693
Commit-Queue: Karen Qian <karenqian@google.com>
Reviewed-by: Aaron Gable <agable@chromium.org>
Cr-Commit-Position: refs/heads/master@{#690923}