Update Mac implemention of Time to prevent problems with...

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"
 
-#ifdef OS_MACOSX
-#include <mach/mach_time.h>
-#endif
 #include <sys/time.h>
 #include <time.h>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 
 namespace base {
 
 // The Time routines in this file use standard POSIX routines, or almost-
 // standard routines in the case of timegm.  We need to use a Mach-specific
@@ skipping 65 matching lines @@
   exploded->second       = timestruct.tm_sec;
   exploded->millisecond  = milliseconds % kMillisecondsPerSecond;
 }
 
 // TimeTicks ------------------------------------------------------------------
 
 // static
 TimeTicks TimeTicks::Now() {
   uint64_t absolute_micro;
 
-#if defined(OS_MACOSX)
-
-  static mach_timebase_info_data_t timebase_info;
-  if (timebase_info.denom == 0) {
-    // Zero-initialization of statics guarantees that denom will be 0 before
-    // calling mach_timebase_info.  mach_timebase_info will never set denom to
-    // 0 as that would be invalid, so the zero-check can be used to determine
-    // whether mach_timebase_info has already been called.  This is
-    // recommended by Apple's QA1398.
-    kern_return_t kr = mach_timebase_info(&timebase_info);
-    DCHECK(kr == KERN_SUCCESS);
-  }
-
-  // mach_absolute_time is it when it comes to ticks on the Mac.  Other calls
-  // with less precision (such as TickCount) just call through to
-  // mach_absolute_time.
-
-  // timebase_info converts absolute time tick units into nanoseconds.  Convert
-  // to microseconds up front to stave off overflows.
-  absolute_micro = mach_absolute_time() / Time::kNanosecondsPerMicrosecond *
-                   timebase_info.numer / timebase_info.denom;
-
-  // Don't bother with the rollover handling that the Windows version does.
-  // With numer and denom = 1 (the expected case), the 64-bit absolute time
-  // reported in nanoseconds is enough to last nearly 585 years.
-
-#elif defined(OS_POSIX) && \
+#if defined(OS_POSIX) && \
       defined(_POSIX_MONOTONIC_CLOCK) && _POSIX_MONOTONIC_CLOCK >= 0
 
   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);
 
 #else  // _POSIX_MONOTONIC_CLOCK
 #error No usable tick clock function on this platform.
 #endif  // _POSIX_MONOTONIC_CLOCK
 
   return TimeTicks(absolute_micro);
 }
 
 // static
 TimeTicks TimeTicks::HighResNow() {
   return Now();
 }
 
 }  // namespace base