IWYU: #include <string.h> for strdup in string_util_posix.h
IWYU: #include <string.h> for strdup in string_util_posix.h

Change-Id: Ibe164d8b7d8fce01ad88d4e56bc4031464982b49
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/mini_chromium/+/3173193
Reviewed-by: Peter Boström <835dd55d2edbcf18427bfaff167a5f261a98c2e0@chromium.org>

chromium/mini_chromium,chromium/mini_chromium,chromium/mini_chromium