Delete IsAtLeastOS10_9() and IsAtMostOS10_9()

sandbox/mac/os_compatibility.cc

 // Copyright 2014 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 "sandbox/mac/os_compatibility.h"
 
 #include <servers/bootstrap.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <unistd.h>
@@ skipping 163 matching lines @@
     return xpc_dictionary_get_bool(message.xpc, "set") == false &&
            xpc_dictionary_get_uint64(message.xpc, "ingsk") == 0 &&
            xpc_dictionary_get_int64(message.xpc, "in") == 0;
   }
 };
 
 }  // namespace
 
 // static
 std::unique_ptr<OSCompatibility> OSCompatibility::CreateForPlatform() {
-  if (base::mac::IsOS10_9())
+  if (base::mac::IsAtLeastOS10_10())
+    return base::WrapUnique(new OSCompatibility_10_10());
+  else
     return base::WrapUnique(new OSCompatibility_10_7());
-  else
-    return base::WrapUnique(new OSCompatibility_10_10());
 }
 
 OSCompatibility::~OSCompatibility() {}
 
 }  // namespace sandbox