Adding native client toolchain download to all chrome checkouts with nacl.

build/download_nacl_toolchains.py

+#!/usr/bin/python
+# Copyright (c) 2011 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.
+
+"""Shim to run nacl toolchain download script only if there is a nacl dir."""
+
+import os
+import sys
+
+
+def Main():
+  script_dir = os.path.dirname(os.path.abspath(__file__))
+  src_dir = os.path.dirname(script_dir)
+  nacl_dir = os.path.join(src_dir, 'native_client')
+  nacl_build_dir = os.path.join(nacl_dir, 'build')
+  download_script = os.path.join(nacl_build_dir, 'download_toolchains.py')
+  if not os.path.exists(download_script):
+    print "Can't find '%s'" % download_script
+    print 'Presumably you are intentionally building without NativeClient.'
+    print 'Skipping NativeClient toolchain download.'
+    sys.exit(0)
+  sys.path.insert(0, nacl_build_dir)
+  import download_toolchains
+  download_toolchains.Main()
+
+
+if __name__ == '__main__':
+  Main()