Moving scripts to download and build apprtc/collider.

We are starting to move code to setup our tests from [1].
We are moving only scripts to download and build apprtc, collider and node
(scripts that work on firefox have not been copied by this CL).

[1] - https://chromium.googlesource.com/chromium/deps/webrtc/webrtc.DEPS/

BUG=webrtc:7602
NOTRY=True

Review-Url: https://codereview.webrtc.org/2861653005
Cr-Commit-Position: refs/heads/master@{#18060}

webrtc/tools/testing/download_apprtc_appengine_and_mercurial.py

@@ -0,0 +1,75 @@
+#!/usr/bin/env python
+# Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+#
+# Use of this source code is governed by a BSD-style license
+# that can be found in the LICENSE file in the root of the source
+# tree. An additional intellectual property rights grant can be found
+# in the file PATENTS.  All contributing project authors may
+# be found in the AUTHORS file in the root of the source tree.
+
+"""Downloads the appengine SDK from WebRTC storage and unpacks it.
+
+Requires that depot_tools is installed and in the PATH.
+
+It downloads compressed files in the directory where the script lives.
+This is because the precondition is that the script lives in the same
+directory of the .sha1 files.
+"""
+
+import glob
+import os
+import sys
+import subprocess
+
+import utils
+
+
+SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
+
+def _DownloadResources(dir_to_scan_for_sha1):
+  print 'Downloading files in %s...' % dir_to_scan_for_sha1
+
+  extension = 'bat' if 'win32' in sys.platform else 'py'
+  cmd = ['download_from_google_storage.%s' % extension,
+         '--bucket=chromium-webrtc-resources',
+         '--directory', dir_to_scan_for_sha1]
+  subprocess.check_call(cmd)
+
+
+def _StripVersionNumberFromMercurialFolder(output_dir):
+  unpacked_name = glob.glob(os.path.join(output_dir, 'mercurial*'))
+  assert len(unpacked_name) == 1, 'Should have precisely one mercurial!'
+  os.rename(unpacked_name[0], os.path.join(output_dir, 'mercurial'))
+
+
+def main(argv):
+  if len(argv) == 1:
+    return 'Usage: %s <output_dir>' % argv[0]
+
+  output_dir = argv[1]
+  appengine_zip_path = os.path.join(SCRIPT_DIR, 'google-appengine.zip')
+  old_appengine_sha1 = utils.ComputeSHA1(appengine_zip_path)
+
+  mercurial_tar_path = os.path.join(SCRIPT_DIR, 'mercurial-src.tar.gz')
+  old_mercurial_sha1 = utils.ComputeSHA1(mercurial_tar_path)
+
+  apprtc_zip_path = os.path.join(SCRIPT_DIR, 'prebuilt_apprtc.zip')
+  old_apprtc_sha1 = utils.ComputeSHA1(apprtc_zip_path)
+
+  _DownloadResources(SCRIPT_DIR)
+
+  if old_appengine_sha1 != utils.ComputeSHA1(appengine_zip_path):
+    utils.RemoveDirectory(os.path.join(output_dir, 'google_appengine'))
+    utils.UnpackArchiveTo(appengine_zip_path, output_dir)
+
+  if old_mercurial_sha1 != utils.ComputeSHA1(mercurial_tar_path):
+    utils.RemoveDirectory(os.path.join(output_dir, 'mercurial'))
+    utils.UnpackArchiveTo(mercurial_tar_path, output_dir)
+    _StripVersionNumberFromMercurialFolder(output_dir)
+
+  if old_apprtc_sha1 != utils.ComputeSHA1(apprtc_zip_path):
+    utils.RemoveDirectory(os.path.join(output_dir, 'apprtc'))
+    utils.UnpackArchiveTo(apprtc_zip_path, output_dir)
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))