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
+
+
+def main():
+  if 'OS=android' not in os.environ.get('GYP_DEFINES', ''):

[mikecase (-- gone --), 2016/02/29 16:35:15]

Not sure if this approach will work after everything is switched over
to GN. Do you know if cronet is switching over to GN soon?

[pauljensen, 2016/02/29 18:48:10]

I don't know when Cronet is switching to GN; I think right now the official
Android buildbots use GYP so we can't switch.  I should note that there are
several download scripts that use GYP_DEFINES:

https://code.google.com/p/chromium/codesearch#search/&q=GYP_DEFINES%20file:%5...

Is there an alternative GN way of determining target build OS for scripts
launched from DEPS from "gclient runhooks"?

[agrieve, 2016/03/01 01:18:45]

There's some relevant discussion in this bug:
https://bugs.chromium.org/p/chromium/issues/detail?id=564869

I think checking for the existence of platform-specific directories is still the
best work-around for now.

[pauljensen, 2016/03/17 14:05:10]

Done.

+    return 0
+  subprocess.check_call([
+      'download_from_google_storage',
+      '--no_resume',
+      '--no_auth',
+      '--bucket', 'chromium-doclava',
+      '--extract',
+      '-s', 'src/buildtools/android/doclava.tar.gz.sha1'])
+  return 0
+
+if __name__ == '__main__':
+  sys.exit(main())