Revert 170800 - Speculatively reverting 166585 to see if it fixes issue 160300 - 6% startup regres…

base/mac/mac_util.h

Index: base/mac/mac_util.h
===================================================================
--- base/mac/mac_util.h	(revision 170849)
+++ base/mac/mac_util.h	(working copy)
@@ -140,9 +140,8 @@
 
 // This should be infrequently used. It only makes sense to use this to avoid
 // codepaths that are very likely to break on future (unreleased, untested,
-// unborn) OS releases.
-BASE_EXPORT
-    bool IsOSDangerouslyLaterThanMountainLionForUseByCFAllocatorReplacement();
+// unborn) OS releases, or to log when the OS is newer than any known version.
+BASE_EXPORT bool IsOSLaterThanMountainLion_DontCallThis();
 
 // When the deployment target is set, the code produced cannot run on earlier
 // OS releases. That enables some of the IsOS* family to be implemented as
@@ -173,8 +172,7 @@
     MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_8
 #define BASE_MAC_MAC_UTIL_H_INLINED_GT_10_8
 inline bool IsOSMountainLion() { return false; }
-inline bool IsOSDangerouslyLaterThanMountainLionForUseByCFAllocatorReplacement()
-{
+inline bool IsOSLaterThanMountainLion_DontCallThis() {
   return true;
 }
 #endif