Provide nanoseconds precision for base::PlatformFileInfo on POSIX

base/time.h

 // 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.
 
 // Time represents an absolute point in time, internally represented as
 // microseconds (s/1,000,000) since the Windows epoch (1601-01-01 00:00:00 UTC)
 // (See http://crbug.com/14734).  System-dependent clock interface routines are
 // defined in time_PLATFORM.cc.
 //
 // TimeDelta represents a duration of time, internally represented in
@@ skipping 268 matching lines @@
   time_t ToTimeT() const;
 
   // Converts time to/from a double which is the number of seconds since epoch
   // (Jan 1, 1970).  Webkit uses this format to represent time.
   // Because WebKit initializes double time value to 0 to indicate "not
   // initialized", we map it to empty Time object that also means "not
   // initialized".
   static Time FromDoubleT(double dt);
   double ToDoubleT() const;
 
+#if defined(OS_POSIX)
+  // Converts the timespec structure to time. MacOS X 10.8.3 (and tentatively,
+  // earlier versions) will have the |ts|'s tv_nsec component zeroed out,
+  // having a 1 second resolution, which agrees with
+  // https://developer.apple.com/legacy/library/#technotes/tn/tn1150.html#HFSPlusDates.
+  static Time FromTimeSpec(const timespec& ts);
+#endif
+
   // Converts to/from the Javascript convention for times, a number of
   // milliseconds since the epoch:
   // https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Date/getTime.
   static Time FromJsTime(double ms_since_epoch);
   double ToJsTime() const;
 
 #if defined(OS_POSIX)
   static Time FromTimeVal(struct timeval t);
   struct timeval ToTimeVal() const;
 #endif
@@ skipping 335 matching lines @@
 #endif
 };
 
 inline TimeTicks TimeDelta::operator+(TimeTicks t) const {
   return TimeTicks(t.ticks_ + delta_);
 }
 
 }  // namespace base
 
 #endif  // BASE_TIME_H_