Android: Add APK patch size estimates to resource_sizes.py.

build/android/binary_size/apk_downloader.py

 #!/usr/bin/python
 # Copyright 2017 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 argparse
 import os
 import sys
 
 _BUILD_ANDROID = os.path.join(os.path.dirname(__file__), os.pardir)
 sys.path.append(_BUILD_ANDROID)
 from pylib.constants import host_paths
 
 sys.path.append(os.path.join(host_paths.DIR_SOURCE_ROOT, 'build'))
 import find_depot_tools  # pylint: disable=import-error,unused-import
 import download_from_google_storage
 
 CURRENT_MILESTONE = '58'
 DEFAULT_BUCKET = 'gs://chromium-android-tools/apks'
 DEFAULT_DOWNLOAD_PATH = os.path.join(os.path.dirname(__file__), 'apks')
 DEFAULT_BUILDER = 'Android_Builder'
 DEFAULT_APK = 'MonochromePublic.apk'
 
 
 def MaybeDownloadApk(builder, milestone, apk, download_path, bucket):
+  """Returns path to the downloaded APK or None if not found."""
   apk_path = os.path.join(download_path, builder, milestone, apk)
   sha1_path = apk_path + '.sha1'
   base_url = os.path.join(bucket, builder, milestone)
   if os.path.exists(apk_path):
     print '%s already exists' % apk_path
+    return apk_path
   elif not os.path.exists(sha1_path):
     print 'Skipping %s, file not found' % sha1_path
+    return None
   else:
     download_from_google_storage.download_from_google_storage(
         input_filename=sha1_path,
         sha1_file=sha1_path,
         base_url=base_url,
         gsutil=download_from_google_storage.Gsutil(
             download_from_google_storage.GSUTIL_DEFAULT_PATH),
         num_threads=1,
         directory=False,
         recursive=False,
         force=False,
         output=apk_path,
         ignore_errors=False,
         verbose=True,
         auto_platform=False,
         extract=False)
+    return apk_path
 
 
 def main():
   argparser = argparse.ArgumentParser(
       description='Utility for downloading archived APKs used for measuring '
                   'per-milestone patch size growth.',
       formatter_class=argparse.ArgumentDefaultsHelpFormatter)
   argparser.add_argument('--download-path', default=DEFAULT_DOWNLOAD_PATH,
                          help='Directory to store downloaded APKs.')
   argparser.add_argument('--milestone', default=CURRENT_MILESTONE,
                          help='Download reference APK for this milestone.')
   argparser.add_argument('--apk', default=DEFAULT_APK, help='APK name.')
   argparser.add_argument('--builder', default=DEFAULT_BUILDER,
                          help='Builder name.')
   argparser.add_argument('--bucket', default=DEFAULT_BUCKET,
                          help='Google storage bucket where APK is stored.')
   args = argparser.parse_args()
   MaybeDownloadApk(
       args.builder, args.milestone, args.apk, args.download_path, args.bucket)
 
 
 if __name__ == '__main__':
   sys.exit(main())