linux: use CLOCK_{REALTIME,MONOTONIC}_COARSE

src/platform/time.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 174 matching lines @@
  public:
   static const int64_t kMillisecondsPerSecond = 1000;
   static const int64_t kMicrosecondsPerMillisecond = 1000;
   static const int64_t kMicrosecondsPerSecond = kMicrosecondsPerMillisecond *
                                                 kMillisecondsPerSecond;
   static const int64_t kMicrosecondsPerMinute = kMicrosecondsPerSecond * 60;
   static const int64_t kMicrosecondsPerHour = kMicrosecondsPerMinute * 60;
   static const int64_t kMicrosecondsPerDay = kMicrosecondsPerHour * 24;
   static const int64_t kMicrosecondsPerWeek = kMicrosecondsPerDay * 7;
   static const int64_t kNanosecondsPerMicrosecond = 1000;
+  static const int64_t kNanosecondsPerMillisecond = kNanosecondsPerMicrosecond *
+                                                    kMicrosecondsPerMillisecond;
   static const int64_t kNanosecondsPerSecond = kNanosecondsPerMicrosecond *
                                                kMicrosecondsPerSecond;
 
   // Contains the NULL time. Use Time::Now() to get the current time.
   Time() : us_(0) {}
 
   // Returns true if the time object has not been initialized.
   bool IsNull() const { return us_ == 0; }
 
   // Returns true if the time object is the maximum time.
@@ skipping 202 matching lines @@
   int64_t ticks_;
 };
 
 inline TimeTicks operator+(const TimeDelta& delta, const TimeTicks& ticks) {
   return ticks + delta;
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_PLATFORM_TIME_H_