GitLab

Actually puts top level hint processing and evaluation behind a new
Feature that is disabled by default (in case we need to revert hints
due to memory footprint or such).

Bug: 902802
Change-Id: I03735e1b724bbcdf32f7cf2eb5025978bc657ca9
Reviewed-on: https://chromium-review.googlesource.com/c/1338301Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Commit-Queue: Doug Arnett <dougarnett@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608509}