Cleanup Semaphore class.

src/platform/time.h

Index: src/platform/time.h
diff --git a/src/platform/time.h b/src/platform/time.h
index 57b894d814b87b862d1e8c687000fd89829218d3..a0d5425b1949a5ce11fcae151834b34d2df6b2ef 100644
--- a/src/platform/time.h
+++ b/src/platform/time.h
@@ -36,6 +36,8 @@
 // Forward declarations.
 extern "C" {
 struct _FILETIME;
+struct mach_timespec;
+struct timespec;
 struct timeval;
 }
 
@@ -82,6 +84,10 @@ class TimeDelta V8_FINAL BASE_EMBEDDED {
   int64_t InMicroseconds() const { return delta_; }
   int64_t InNanoseconds() const;
 
+  // Converts to/from Mach time specs.
+  static TimeDelta FromMachTimespec(struct mach_timespec ts);
+  struct mach_timespec ToMachTimespec() const;
+
   TimeDelta& operator=(const TimeDelta& other) {
     delta_ = other.delta_;
     return *this;
@@ -212,6 +218,10 @@ class Time V8_FINAL BASE_EMBEDDED {
   // with which we might compare it.
   static Time Max() { return Time(std::numeric_limits<int64_t>::max()); }
 
+  // Converts to/from POSIX time specs.
+  static Time FromTimespec(struct timespec ts);
+  struct timespec ToTimespec() const;
+
   // Converts to/from POSIX time values.
   static Time FromTimeval(struct timeval tv);
   struct timeval ToTimeval() const;