Do not enforce HEAD when a revision is not specified.

This brings back git cl try to try at LKGR instead of HEAD, which is coherent
with git-try and gcl try.

R=rogerta@chromium.org
BUG=


Review URL: https://chromiumcodereview.appspot.com/10963013

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@157810 0039d316-1c4b-4281-b951-d872f2087c98

git_cl.py

@@ -1598,6 +1598,10 @@ def CMDtry(parser, args):
   cl.RpcServer().trigger_try_jobs(
       cl.GetIssue(), patchset, options.name, options.clobber, options.revision,
       builders_and_tests)
+  print('Tried jobs on:')
+  length = max(len(builder) for builder in builders_and_tests)
+  for builder in sorted(builders_and_tests):
+    print '  %*s: %s' % (length, builder, ','.join(builders_and_tests[builder]))
   return 0
 
 

rietveld.py

@@ -315,10 +315,11 @@ class Rietveld(object):
     params = [
       ('reason', reason),
       ('clobber', 'True' if clobber else 'False'),
-      ('revision', revision if revision else 'HEAD'),
       ('builders', json.dumps(builders_and_tests)),
       ('xsrf_token', self.xsrf_token()),
     ]
+    if revision:
+      params.append(('revision', revision))
     return self.post('/%d/try/%d' % (issue, patchset), params)
 
   def get_pending_try_jobs(self, cursor=None, limit=100):