CSS font-variation-settings: retire feature flag

font-variation-settings shipped to stable in M62.

The CSSVariableFonts feature flag is no longer needed.

BUG=669453

Change-Id: I3061318331dda4f12a325caea49296b64cd8a05f
Reviewed-on: https://chromium-review.googlesource.com/892759
Reviewed-by: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Eric Willigers <ericwilligers@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533036}
4 files changed