Mac: Avoid deprecated use of ::Gestalt() in base/sys_info_mac

base/BUILD.gn

 # Copyright (c) 2013 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.
 
 # HOW TO WRITE CONDITIONALS IN THIS FILE
 # ======================================
 #
 # In many other places, one would write a conditional that expresses all the
 # cases when a source file is used or unused, and then either add or subtract
 # it from the sources list in that case
@@ skipping 737 matching lines @@
     "synchronization/waitable_event_win.cc",
     "sys_byteorder.h",
     "sys_info.cc",
     "sys_info.h",
     "sys_info_android.cc",
     "sys_info_chromeos.cc",
 
     #"sys_info_freebsd.cc",  # Unused in Chromium build.
     "sys_info_ios.mm",
     "sys_info_linux.cc",
-    "sys_info_mac.cc",
+    "sys_info_mac.mm",
 
     #"sys_info_openbsd.cc",  # Unused in Chromium build.
     "sys_info_posix.cc",
     "sys_info_win.cc",
     "system_monitor/system_monitor.cc",
     "system_monitor/system_monitor.h",
     "task/cancelable_task_tracker.cc",
     "task/cancelable_task_tracker.h",
     "task_runner.cc",
     "task_runner.h",
@@ skipping 1552 matching lines @@
 
   # GYP: //base.gyp:base_java_unittest_support
   android_library("base_java_unittest_support") {
     deps = [
       ":base_java",
     ]
     java_files =
         [ "test/android/java/src/org/chromium/base/ContentUriTestUtils.java" ]
   }
 }