Enable WebFonts cache-aware timeout adaption

Enable the feature by default, but with a FeatureList kill-switch.

Bug: 570205
Change-Id: I003c21871ab71e47a863707b9709a39d76883635
Reviewed-on: https://chromium-review.googlesource.com/c/1429820
Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
Reviewed-by: Kunihiko Sakamoto <ksakamoto@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Takashi Toyoshima <toyoshim@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#626969}(cherry picked from commit 67bee39340b5b4f5b361a0423391c044d13dd332)
Reviewed-on: https://chromium-review.googlesource.com/c/1446263
Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org>
Cr-Commit-Position: refs/branch-heads/3683@{#85}
Cr-Branched-From: e51029943e0a38dd794b73caaf6373d5496ae783-refs/heads/master@{#625896}
8 files changed