[presubmit] Enable runtime/threadsafe_fn linter checking.

src/base/platform/platform-openbsd.cc

Index: src/base/platform/platform-openbsd.cc
diff --git a/src/base/platform/platform-openbsd.cc b/src/base/platform/platform-openbsd.cc
index e5b159ba36a898539756d33fd925b3e6f062ca6e..369dd8e1a6da3ad7cc792758d2dc928e9fcc16d6 100644
--- a/src/base/platform/platform-openbsd.cc
+++ b/src/base/platform/platform-openbsd.cc
@@ -37,7 +37,7 @@ namespace base {
 const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
   if (std::isnan(time)) return "";
   time_t tv = static_cast<time_t>(std::floor(time/msPerSecond));
-  struct tm* t = localtime(&tv);
+  struct tm* t = localtime(&tv);  // NOLINT(runtime/threadsafe_fn)
   if (NULL == t) return "";
   return t->tm_zone;
 }
@@ -45,7 +45,7 @@ const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
 
 double OS::LocalTimeOffset(TimezoneCache* cache) {
   time_t tv = time(NULL);
-  struct tm* t = localtime(&tv);
+  struct tm* t = localtime(&tv);  // NOLINT(runtime/threadsafe_fn)
   // tm_gmtoff includes any daylight savings offset, so subtract it.
   return static_cast<double>(t->tm_gmtoff * msPerSecond -
                              (t->tm_isdst > 0 ? 3600 * msPerSecond : 0));