Removed virtualenv from depot_tools

This effectively reverts http://crrev.com/1195423002 and
http://crrev.com/1205873002.

R=pgervais@chromium.org, tandrii@chromium.org
TBR=pgervais@chromium.org  # i wanna get my Fixit credit today :-)
BUG=542922,503067

Review URL: https://codereview.chromium.org/1437483002 .

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@297491 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 41c56d3..2877144 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -22,8 +22,7 @@
       r'^python[0-9]*_bin[\/\\].+',
       r'^site-packages-py[0-9]\.[0-9][\/\\].+',
       r'^svn_bin[\/\\].+',
-      r'^testing_support[\/\\]_rietveld[\/\\].+',
-      r'^bootstrap[\/\\].+']
+      r'^testing_support[\/\\]_rietveld[\/\\].+']
   if os.path.exists('.gitignore'):
     with open('.gitignore') as fh:
       lines = [l.strip() for l in fh.readlines()]