Enable system trace clock use on chrome os.

base/time_posix.cc

 // Copyright (c) 2012 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 <unistd.h>
 
 #include <limits>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 
 #if defined(OS_ANDROID)
 #include "base/os_compat_android.h"
 #elif defined(OS_NACL)
 #include "base/os_compat_nacl.h"
 #endif
 
 namespace base {
 
 #if defined(OS_ANDROID)
 #define _POSIX_MONOTONIC_CLOCK 1
 #endif
+#if defined(OS_CHROMEOS)
+// Force definition of the system trace clock; it is a chromeos-only api
+// at the moment and surfacing it in the right place requires mucking
+// with glibc et al.
+#define CLOCK_SYSTEM_TRACE 11
+#endif
 
 struct timespec TimeDelta::ToTimeSpec() const {
   int64 microseconds = InMicroseconds();
   time_t seconds = 0;
   if (microseconds >= Time::kMicrosecondsPerSecond) {
     seconds = InSeconds();
     microseconds -= seconds * Time::kMicrosecondsPerSecond;
   }
   struct timespec result =
       {seconds,
@@ skipping 223 matching lines @@
 
 struct timeval Time::ToTimeVal() const {
   struct timeval result;
   int64 us = us_ - kTimeTToMicrosecondsOffset;
   result.tv_sec = us / Time::kMicrosecondsPerSecond;
   result.tv_usec = us % Time::kMicrosecondsPerSecond;
   return result;
 }
 
 }  // namespace base