[Reland] Roll sysroots

> Also needed is [1] in webrtc, which fixes some build warnings. Could
> land in parallel.
>
> [1] https://webrtc-review.googlesource.com/c/src/+/156980
>
> BUG=1012850
>
> Change-Id: Ia24e490db5e71cf1add0e10f4c1264aefb69143c
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1859935
> Auto-Submit: Thomas Anderson <thomasanderson@chromium.org>
> Reviewed-by: Dirk Pranke <dpranke@chromium.org>
> Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#705589}

BUG=1012850
R=dpranke

Change-Id: I1a3113201042d09931c0fe1ec68fe494b1b70df2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1862623
Auto-Submit: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#706370}
12 files changed