Remove support for multivm branch and runners

tools/dartium/update_deps.py

 #!/usr/bin/python
 
 # Update Dartium DEPS automatically.
 
 from datetime import datetime, timedelta
 import optparse
 import os
 import re
 from subprocess import Popen, PIPE
 import sys
@@ skipping 11 matching lines @@
 #
 #  (c) Checkout dart/tools/dartium (with this script):
 #      > svn co https://dart.googlecode.com/svn/branches/bleeding_edge/dart/tools/dartium dartium_tools
 #
 #  (d) If your home directory is remote, consider redefining it for this shell/script:
 #      > cp -R $HOME/.subversion /usr/local/google/home/$USER
 #      > export HOME=/usr/local/google/home/$USER
 #
 #  (e) Test by running (Ctrl-C to quit):
 #      > ./dartium_tools/update_deps.py
-#      > ./dartium_tools/update_deps.py --target=multivm
 #      > ./dartium_tools/update_deps.py --target=clank
 #      > ./dartium_tools/update_deps.py --target=integration
 #
 #  (f) Run periodical update:
 #      > while true; do ./dartium_tools/update_deps.py --force ; sleep 300 ; done
 
 ########################################################################
 # Repositories to auto-update
 ########################################################################
 
@@ skipping 219 matching lines @@
   if not options.force:
     print "Ready to push; press Enter to continue or Control-C to abort..."
     sys.stdin.readline()
   print run_cmd(['git', 'commit', '-F', 'commit_log.txt'])
   print run_cmd(['git', 'push', repo_branch_parts[0], repo_branch_parts[1]])
   print "Done."
 
 
 if '__main__' == __name__:
   main()