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..660667d89b1e2a9d3bf57d7d2da81be762957788 100755
--- a/build/mac/find_sdk.py
+++ b/build/mac/find_sdk.py
@@ -40,6 +40,13 @@ def main():
     parser.error('Please specify a minimum SDK version')
   min_sdk_version = args[0]
 
+  # Try using the toolchain in mac_files.
+  sys.path.append(os.path.dirname(os.path.dirname(__file__)))
+  import mac_toolchain

[erikchen, 2016/03/30 17:39:55]

I've seen python files in our code base that would have these two lines at the
top of the file, along with imports. Would that be cleaner?

[justincohen, 2016/03/30 21:14:26]

Done.

+  mac_toolchain_dir = mac_toolchain.GetToolchainDirectory()
+  if mac_toolchain_dir:
+     os.environ['DEVELOPER_DIR'] = mac_toolchain_dir

[erikchen, 2016/03/30 17:39:55]

2 space indent?

Given that this logic is also present in build/gyp_environment.py, should we
make a new method in mac_toolchain_dir? Mostly trying to avoid duplicated static
strings.

[justincohen, 2016/03/30 21:14:26]

Done.

+
   job = subprocess.Popen(['xcode-select', '-print-path'],
                          stdout=subprocess.PIPE,
                          stderr=subprocess.STDOUT)