Add --force option for presubmit command which

allows one to run the presubmit script without
submitting locally (alternative would be to make 
this a warning I guess).

Also, pass option.verbose through to DoGetTrySlaves()
so it will log which PRESUBMIT files are taking part
in the decision.

BUG=

Review URL: https://chromiumcodereview.appspot.com/10915072

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@154838 0039d316-1c4b-4281-b951-d872f2087c98

git_cl.py

@@ -926,13 +926,16 @@ def CMDpresubmit(parser, args):
   """run presubmit tests on the current changelist"""
   parser.add_option('--upload', action='store_true',
                     help='Run upload hook instead of the push/dcommit hook')
+  parser.add_option('--force', action='store_true',
+                    help='Run checks even if tree is dirty')
   (options, args) = parser.parse_args(args)
 
   # Make sure index is up-to-date before running diff-index.
   RunGit(['update-index', '--refresh', '-q'], error_ok=True)
-  if RunGit(['diff-index', 'HEAD']):
+  if not options.force and RunGit(['diff-index', 'HEAD']):
     # TODO(maruel): Is this really necessary?
-    print 'Cannot presubmit with a dirty tree.  You must commit locally first.'
+    print ('Cannot presubmit with a dirty tree.\n'
+          'You must commit locally first (or use --force).')
     return 1
 
   cl = Changelist()

trychange.py

@@ -819,7 +819,7 @@ def TryChange(argv,
             checkouts[0].checkout_root,
             root_presubmit,
             options.project,
-            False,
+            options.verbose,
             sys.stdout)
       except ImportError:
         pass