Grit: Don't attempt to inline srcset="$i18n{foo}" occurrences.

This allows replacing the last i18n-values usage in plugin_poster.html
(also done in this CL), which further unblocks the i18n-values to $i18n{}
migration.

Bug: 936220
Change-Id: Ib53347621854b69dd13331fcc81601cf0654b9f3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1490404
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Dan Beam <dbeam@chromium.org>
Reviewed-by: Tommy Li <tommycli@chromium.org>
Commit-Queue: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#640992}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 4680e2e63630a16d48c88c7e65e829ba851c1598
2 files changed