Add mac toolchain script support to find_sdk script.

build/mac/find_sdk.py

Index: build/mac/find_sdk.py
diff --git a/build/mac/find_sdk.py b/build/mac/find_sdk.py
index ec1c96cfc7aa158fb4435c129497e83d7752bb69..ce23524c0fd57631722d643e7e210f292afe5c1d 100755
--- a/build/mac/find_sdk.py
+++ b/build/mac/find_sdk.py
@@ -15,6 +15,8 @@ import re
 import subprocess
 import sys
 
+sys.path.append(os.path.dirname(os.path.dirname(__file__)))
+import mac_toolchain
 
 from optparse import OptionParser
 
@@ -40,6 +42,9 @@ def main():
     parser.error('Please specify a minimum SDK version')
   min_sdk_version = args[0]
 
+  # Try using the toolchain in mac_files.
+  mac_toolchain.SetToolchainEnvironment()
+
   job = subprocess.Popen(['xcode-select', '-print-path'],
                          stdout=subprocess.PIPE,
                          stderr=subprocess.STDOUT)