Add GN arg to remove the warning supression in jsoncpp

Projects using jsoncpp can then disable the suppression by
overriding the default value in their .gn file, preventing
accidental missed deprecated usage.

Bug: 983223
Change-Id: I9f6f5c72e50350ba3c2400760e11d1358c6ec77b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3571752
Reviewed-by: Mirko Bonadei <mbonadei@chromium.org>
Reviewed-by: Jordan Bayles <jophba@chromium.org>
Commit-Queue: Jordan Bayles <jophba@chromium.org>
Cr-Commit-Position: refs/heads/main@{#990507}
NOKEYCHECK=True
GitOrigin-RevId: e47c02d308c80fa0335283a0e4716eb620b8ef33
1 file changed