Kills TraceTicks, which was functionally the same as TimeTicks

base/time/time_mac.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/time.h"
 
 #include <CoreFoundation/CFDate.h>
 #include <CoreFoundation/CFTimeZone.h>
 #include <mach/mach.h>
 #include <mach/mach_time.h>
@@ skipping 213 matching lines @@
 // static
 bool TimeTicks::IsHighResolution() {
   return true;
 }
 
 // static
 ThreadTicks ThreadTicks::Now() {
   return ThreadTicks(ComputeThreadTicks());
 }
 
-// static
-TraceTicks TraceTicks::Now() {
-  return TraceTicks(ComputeCurrentTicks());
-}
-
 }  // namespace base