In rebaseline.py, update SCM and expectations all at once after all commands.

third_party/WebKit/Tools/Scripts/webkitpy/tool/commands/optimize_baselines_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 optparse
 
 from webkitpy.common.system.outputcapture import OutputCapture
 from webkitpy.tool.commands.optimize_baselines import OptimizeBaselines
 from webkitpy.tool.commands.rebaseline_unittest import BaseTestCase
 
@@ skipping 57 matching lines @@
             self.command.execute(
                 optparse.Values({'suffixes': 'txt,wav,png', 'no_modify_scm': True, 'platform': 'test-mac-mac10.10'}),
                 ['another/test.html'],
                 self.tool)
         finally:
             out, _, _ = oc.restore_output()
 
         self.assertEquals(
             out,
             '{"add": [], "remove-lines": [], '
-            '"delete": ["/test.checkout/LayoutTests/platform/test-mac-mac10.10/another/test-expected.txt", '
-            '"/test.checkout/LayoutTests/platform/test-mac-mac10.10/another/test-expected.png"]}\n')
+            '"delete": ["/test.checkout/LayoutTests/platform/test-mac-mac10.10/another/test-expected.png", '
+            '"/test.checkout/LayoutTests/platform/test-mac-mac10.10/another/test-expected.txt"]}\n')
         self.assertFalse(
             self.tool.filesystem.exists(self.tool.filesystem.join(
                 test_port.layout_tests_dir(), 'platform/mac/another/test-expected.txt')))
         self.assertFalse(
             self.tool.filesystem.exists(self.tool.filesystem.join(
                 test_port.layout_tests_dir(), 'platform/mac/another/test-expected.png')))
         self.assertTrue(
             self.tool.filesystem.exists(self.tool.filesystem.join(
                 test_port.layout_tests_dir(), 'another/test-expected.txt')))
         self.assertTrue(
             self.tool.filesystem.exists(self.tool.filesystem.join(
                 test_port.layout_tests_dir(), 'another/test-expected.png')))