Fixed gcc 4.7 build problem for glmark2 tarbarll.

Added explict <unistd.h> inclusion to "libmartrix/log.cc".

TEST=manually, built with gcc 4.7
BUG=None

Change-Id: I261e95b6311ec1be40e444230baf65c825cdc0da
Reviewed-on: https://gerrit.chromium.org/gerrit/25770
Reviewed-by: asharif <asharif@chromium.org>
Commit-Ready: Han Shen <shenhan@google.com>
Tested-by: Han Shen <shenhan@google.com>
1 file changed