[iOS] Roll text-fragments-polyfill to silence unreachable code warning.

Bug: 1136043
Change-Id: I2caa0b769cc08dd071d55336ca9202548f0dc433
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2521705


Commit-Queue: Sebastien Lalancette <seblalancette@chromium.org>
Commit-Queue: sebsg <sebsg@chromium.org>
Commit-Queue: Tommy Martino <tmartino@chromium.org>
Auto-Submit: Sebastien Lalancette <seblalancette@chromium.org>
Reviewed-by: sebsg <sebsg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824905}