Add a revision flag for try_perf.py

tools/try_perf.py

 #!/usr/bin/env python
 # Copyright 2014 the V8 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.
 
 import argparse
 import os
 import subprocess
 import sys
 
@@ skipping 35 matching lines @@
   'sunspider',
 ]
 
 V8_BASE = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
 
 def main():
   parser = argparse.ArgumentParser(description='')
   parser.add_argument('benchmarks', nargs='+', help='The benchmarks to run.')
   parser.add_argument('--extra-flags', default='',
                       help='Extra flags to be passed to the executable.')
+  parser.add_argument('-r', '--revision', type=str, default=None,
+                      help='Revision (use full hash!) to use for the try job; '
+                           'default: the revision will be determined by the '
+                           'try server; see its waterfall for more info')
   for option in sorted(BOTS):
     parser.add_argument(
         option, dest='bots', action='append_const', const=BOTS[option],
         help='Add %s trybot.' % BOTS[option])
   options = parser.parse_args()
   if not options.bots:
     print 'No trybots specified. Using default %s.' % ','.join(DEFAULT_BOTS)
     options.bots = DEFAULT_BOTS
 
   if not options.benchmarks:
@@ skipping 12 matching lines @@
 
   assert '"' not in options.extra_flags and '\'' not in options.extra_flags, (
       'Invalid flag specification.')
 
   # Ensure depot_tools are updated.
   subprocess.check_output(
       'gclient', shell=True, stderr=subprocess.STDOUT, cwd=V8_BASE)
 
   cmd = ['git cl try -m internal.client.v8']
   cmd += ['-b %s' % bot for bot in options.bots]
+  if options.revision: cmd += ['-r %s' % options.revision]
   benchmarks = ['"%s"' % benchmark for benchmark in options.benchmarks]
   cmd += ['-p \'testfilter=[%s]\'' % ','.join(benchmarks)]
   if options.extra_flags:
     cmd += ['-p \'extra_flags="%s"\'' % options.extra_flags]
   subprocess.check_call(' '.join(cmd), shell=True, cwd=V8_BASE)
 
 
 if __name__ == '__main__':  # pragma: no cover
   sys.exit(main())