Use CHROME_HEADLESS to check if download_sdk_extras.py is running on a bot.

build/download_sdk_extras.py

 #!/usr/bin/env python
 # Copyright 2014 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.
 
 """Script to download sdk/extras packages on the bots from google storage.
 
 The script expects arguments that specify zips file in the google storage
 bucket named: <dir in SDK extras>_<package name>_<version>.zip. The file will
-be extracted in the android_tools/sdk/extras directory.
+be extracted in the android_tools/sdk/extras directory on the test bots. This
+script will not do anything for developers.
 """
 
 import json
 import os
 import shutil
 import subprocess
 import sys
 import zipfile
 
-sys.path.insert(0, os.path.join(os.path.dirname(__file__), 'android'))
+SCRIPT_DIR = os.path.dirname(os.path.realpath(__file__))
+CHROME_SRC = os.path.abspath(os.path.join(SCRIPT_DIR, os.pardir))
+sys.path.insert(0, os.path.join(SCRIPT_DIR, 'android'))
+sys.path.insert(1, os.path.join(CHROME_SRC, 'tools'))
+
 from pylib import constants
+import find_depot_tools
 
-GSUTIL_PATH = os.path.join(os.path.dirname(__file__), os.pardir, os.pardir,
-    os.pardir, os.pardir, os.pardir, os.pardir, 'depot_tools', 'gsutil.py')
+DEPOT_PATH = find_depot_tools.add_depot_tools_to_path()
+GSUTIL_PATH = os.path.join(DEPOT_PATH, 'gsutil.py')
 SDK_EXTRAS_BUCKET = 'gs://chrome-sdk-extras'
 SDK_EXTRAS_PATH = os.path.join(constants.ANDROID_SDK_ROOT, 'extras')
 SDK_EXTRAS_JSON_FILE = os.path.join(os.path.dirname(__file__),
                                     'android_sdk_extras.json')
 
 
 def clean_and_extract(dir_name, package_name, zip_file):
   local_dir = '%s/%s/%s' % (SDK_EXTRAS_PATH, dir_name, package_name)
   if os.path.exists(local_dir):
     shutil.rmtree(local_dir)
   local_zip = '%s/%s' % (SDK_EXTRAS_PATH, zip_file)
   with zipfile.ZipFile(local_zip) as z:
     z.extractall(path=SDK_EXTRAS_PATH)
 
 
 def main():
-  if not os.path.exists(GSUTIL_PATH) or not os.path.exists(SDK_EXTRAS_PATH):
+  if not os.environ.get('CHROME_HEADLESS'):
     # This is not a buildbot checkout.
     return 0
   # Update the android_sdk_extras.json file to update downloaded packages.
   with open(SDK_EXTRAS_JSON_FILE) as json_file:
     packages = json.load(json_file)
   for package in packages:
     local_zip = '%s/%s' % (SDK_EXTRAS_PATH, package['zip'])
     if not os.path.exists(local_zip):
       package_zip = '%s/%s' % (SDK_EXTRAS_BUCKET, package['zip'])
-      subprocess.check_call([GSUTIL_PATH, '--force-version', '4.7', 'cp',
-                            package_zip, local_zip])
+      subprocess.check_call(['python', GSUTIL_PATH, '--force-version', '4.7',
+                             'cp', package_zip, local_zip])
     # Always clean dir and extract zip to ensure correct contents.
     clean_and_extract(package['dir_name'], package['package'], package['zip'])
 
 
 if __name__ == '__main__':
   sys.exit(main())