Port some of the base system to FreeBSD. Extracted from...

base/time_posix.cc

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/time.h"
 
 #include <sys/time.h>
 #include <time.h>
 
 #include <limits>
@@ skipping 125 matching lines @@
   exploded->month        = timestruct.tm_mon + 1;
   exploded->day_of_week  = timestruct.tm_wday;
   exploded->day_of_month = timestruct.tm_mday;
   exploded->hour         = timestruct.tm_hour;
   exploded->minute       = timestruct.tm_min;
   exploded->second       = timestruct.tm_sec;
   exploded->millisecond  = milliseconds % kMillisecondsPerSecond;
 }
 
 // TimeTicks ------------------------------------------------------------------
-
-#if defined(OS_POSIX) && \
-    defined(_POSIX_MONOTONIC_CLOCK) && _POSIX_MONOTONIC_CLOCK >= 0
+// FreeBSD 6 has CLOCK_MONOLITHIC but defines _POSIX_MONOTONIC_CLOCK to -1
+#if (defined(OS_POSIX) &&                                               \
+     defined(_POSIX_MONOTONIC_CLOCK) && _POSIX_MONOTONIC_CLOCK >= 0) || \
+    defined(OS_FREEBSD)
 
 // static
 TimeTicks TimeTicks::Now() {
   uint64_t absolute_micro;
 
   struct timespec ts;
   if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0) {
     NOTREACHED() << "clock_gettime(CLOCK_MONOTONIC) failed.";
     return TimeTicks();
   }
 
   absolute_micro =
       (static_cast<int64>(ts.tv_sec) * Time::kMicrosecondsPerSecond) +
       (static_cast<int64>(ts.tv_nsec) / Time::kNanosecondsPerMicrosecond);
 
   return TimeTicks(absolute_micro);
 }
 
 #else  // _POSIX_MONOTONIC_CLOCK
 #error No usable tick clock function on this platform.
 #endif  // _POSIX_MONOTONIC_CLOCK
 
 // static
 TimeTicks TimeTicks::HighResNow() {
   return Now();
 }
 
 }  // namespace base