GitLab

Combines the GetSwitchesFromFlags() and GetFeaturesFromFlags()
calls to avoid GenerateFlagsToSwitchesMapping() being called
twice, which we have evidence of being expensive.

Bug: 904575
Change-Id: Ie89acad8175fdfe029a951074b9aa1f4f7678f95
Reviewed-on: https://chromium-review.googlesource.com/c/1333875
Commit-Queue: Alexei Svitkine <asvitkine@chromium.org>
Reviewed-by: ssid <ssid@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608005}