rebaseline-cl: Get latest try jobs using git-cl when no --issue given.

third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/rebaseline_cl_unittest.py

 # Copyright 2016 The Chromium 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 json
 import optparse
 
 from webkitpy.common.net.buildbot import Build
 from webkitpy.common.net.git_cl import GitCL
 from webkitpy.common.net.layout_test_results import LayoutTestResults
@@ skipping 158 matching lines @@
     def test_execute_with_no_issue_number(self):
         return_code = self.command.execute(self.command_options(), [], self.tool)
         self.assertEqual(return_code, 1)
         self.assertLog(['ERROR: No issue number given and no issue for current branch. This tool requires a CL\n'
                         'to operate on; please run `git cl upload` on this branch first, or use the --issue\n'
                         'option to download baselines for another existing CL.\n'])
 
     def test_execute_with_issue_number_from_branch(self):
         git_cl = GitCL(self.tool)
         git_cl.get_issue_number = lambda: '11112222'
+        git_cl.latest_try_jobs = lambda _: [Build('MOCK Try Win', 5000)]
         self.command.git_cl = lambda: git_cl
         return_code = self.command.execute(self.command_options(), [], self.tool)
         self.assertEqual(return_code, 0)
         self.assertLog([
             'INFO: Rebaselining fast/dom/prototype-inheritance.html\n',
             'INFO: Rebaselining fast/dom/prototype-newtest.html\n',
             'INFO: Rebaselining fast/dom/prototype-slowtest.html\n',
             'INFO: Rebaselining fast/dom/prototype-taco.html\n',
             'INFO: Rebaselining svg/dynamic-updates/SVGFEDropShadowElement-dom-stdDeviation-attr.html\n',
         ])
@@ skipping 130 matching lines @@
 
     def test_bails_when_there_are_unstaged_baselines(self):
         git = self.tool.git()
         git.unstaged_changes = lambda: {'third_party/WebKit/LayoutTests/my-test-expected.txt': '?'}
         return_code = self.command.execute(self.command_options(issue=11112222), [], self.tool)
         self.assertEqual(return_code, 1)
         self.assertLog([
             'ERROR: Aborting: there are unstaged baselines:\n',
             'ERROR:   /mock-checkout/third_party/WebKit/LayoutTests/my-test-expected.txt\n',
         ])