Download doclava when building for Android and use to build cronet Javadocs

build/android/download_doclava.py

+#!/usr/bin/env python
+# Copyright 2016 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.
+
+"""Minimal tool to download doclava from Google storage when building for
+Android."""
+
+import os
+import subprocess
+import sys
+
+
+# Its existence signifies an Android checkout.
+ANDROID_ONLY_DIR = os.path.join(os.path.dirname(os.path.abspath(__file__)),
+                                os.pardir, os.pardir,
+                                'third_party', 'android_tools')
+
+
+def main():
+  # Some Windows bots inadvertently have third_party/android_tools installed,
+  # but are unable to run download_from_google_storage because depot_tools
+  # is not in their path, so avoid failure and bail.
+  if sys.platform == 'win32':
+    return 0
+  if not os.path.exists(ANDROID_ONLY_DIR):
+    return 0
+  subprocess.check_call([
+      'download_from_google_storage',
+      '--no_resume',
+      '--no_auth',
+      '--bucket', 'chromium-doclava',
+      '--extract',
+      '-s',
+      os.path.join('src', 'buildtools', 'android', 'doclava.tar.gz.sha1')])
+  return 0
+
+if __name__ == '__main__':
+  sys.exit(main())