Re-land: Added virtualenv for depot_tools

update_depot_tools

 #!/usr/bin/env bash
 # Copyright (c) 2012 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.
 
 # This script will try to sync the bootstrap directories and then defer control.
 
 if [ "$USER" == "root" ];
 then
   echo Running depot tools as root is sad.
@@ skipping 135 matching lines @@
   "$SVN" -q up "$base_dir"
   AFTER_REVISION=$(get_svn_revision)
   if [[ "$BEFORE_REVISION" != "$AFTER_REVISION" ]]; then
     if [ -z "$DEPOT_TOOLS_HIDE_UPDATED_MESSAGE" ]; then
       echo "Depot Tools has been updated to revision $AFTER_REVISION." 1>&2
     fi
   fi
 fi
 
 find "$base_dir" -iname "*.pyc" -exec rm {} \;
+
+# Initialize/update virtualenv.
+VIRTUALENV_REPO="https://chromium.googlesource.com/infra/third_party/virtualenv.git"
+VIRTUALENV_REVISION="4243b272823228dde5d18a7400c404ce52fb4cea"

[pgervais, 2015/06/24 16:31:33]

Virtualenv is vendored in infra.git/bootstrap/virtualenv, we should do the same
here (put it in third_party instead if you want).

We really don't want to depend on yet another network connection on all slaves.

[Sergiy Byelozyorov, 2015/06/25 14:42:17]

It's checked out with DEPS. I thought 'vendored' means 'copied'. We can't use
DEPS here since gclient is not set up yet. Also there are other commands using
network here... why adding another one makes it worse?

[pgervais, 2015/06/25 17:12:02]

Yes 'vendored' means copied. The idea behind Glyco is to vendor everything (in
depot_tools) anyway.

I ack the fact that this file uses the network already, but it's also a question
of atomicity. If git fetch fails, no big deal. If git fetch succeeds but
downloading virtualenv fails, we end up in  a weird situation. BTW with the
current code we have no way to update virtualenv. We'll need some more logic to
fix it, which can also break, etc. The simpler the better.

[Sergiy Byelozyorov, 2015/06/25 17:34:51]

Done.

+cd $base_dir
+if [ ! -d bootstrap/virtualenv ]; then
+  echo "Fetching virtualenv from $VIRTUALENV_REPO@$VIRTUALENV_REVISION"
+  eval "$GIT" clone "$VIRTUALENV_REPO" bootstrap/virtualenv --no-checkout --quiet
+  cd bootstrap/virtualenv
+  eval "$GIT" checkout "$VIRTUALENV_REVISION" --quiet
+  cd ../..
+  echo "Done fetching virtualenv"
+fi
+python -u ./bootstrap/bootstrap.py --deps_file bootstrap/deps.pyl --quiet ENV