Revert of SkTime::GetNSecs()

src/core/SkTime.cpp

Index: src/core/SkTime.cpp
diff --git a/src/core/SkTime.cpp b/src/core/SkTime.cpp
index 72b9aced5179d5e079faab783a8254bfb1ca5b71..fa6c04447de0ade9f8bfaf927151215d6eec85ec 100644
--- a/src/core/SkTime.cpp
+++ b/src/core/SkTime.cpp
@@ -22,26 +22,3 @@
                     timeZoneMinutes);
     }
 }
-
-// TODO: use std::chrono on Mach too, when available.
-
-#if defined(__MACH__)
-    #include "SkOncePtr.h"
-    #include <mach/mach_time.h>
-    SK_DECLARE_STATIC_ONCE_PTR(double, ns_per_tick);
-    double SkTime::GetNSecs() {
-        uint64_t ticks = mach_absolute_time();
-        return ticks * *ns_per_tick.get([]{
-            mach_timebase_info_data_t timebase;
-            (void)mach_timebase_info(&timebase);
-            return new double(timebase.numer * 1.0 / timebase.denom);
-        });
-    }
-#else
-    #include <chrono>
-    double SkTime::GetNSecs() {
-        auto now = std::chrono::high_resolution_clock::now();
-        std::chrono::duration<double, std::nano> ns = now.time_since_epoch();
-        return ns.count();
-    }
-#endif