Add mac hermetic support to build/config/mac/sdk_info.py.

build/config/mac/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.
 
 import("//build/config/sysroot.gni")
-import("//build/config/ios/ios_sdk.gni")
+if (is_ios) {
+  import("//build/config/ios/ios_sdk.gni")
+}
 import("//build/config/mac/mac_sdk.gni")
 import("//build/config/mac/symbols.gni")
 
 # This is included by reference in the //build/config/compiler config that
 # is applied to all targets. It is here to separate out the logic.
 #
 # This is applied to BOTH desktop Mac and iOS targets.
 config("compiler") {
   # These flags are shared between the C compiler and linker.
   common_mac_flags = []
@@ skipping 106 matching lines @@
     # after running "lipo" too.
     _enable_stripping = false
   } else {
     _enable_stripping = enable_stripping
   }
 
   if (_enable_stripping) {
     ldflags = [ "-Wcrl,strip,-x,-S" ]
   }
 }