Fix resolution of local branch name in scm and rebaseline tools.

Tools/Scripts/webkitpy/tool/commands/rebaseline.py

 # Copyright (c) 2010 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 825 matching lines @@
         did_finish = False
         try:
             # Setup git-svn for dcommit if necessary.
             if tool.executive.run_command(
                     ['git', 'config', '--local', '--get-regexp', r'^svn-remote\.'],
                     return_exit_code=True):
                 tool.executive.run_command(['git', 'auto-svn'])
 
             # Save the current branch name and checkout a clean branch for the patch.
             old_branch_name = tool.executive.run_command(
-                ["git", "rev-parse", "--symbolic-full-name", "HEAD"])
+                ["git", "rev-parse", "--symbolic-full-name", "HEAD"]).strip()

[Xianzhu, 2015/07/15 21:16:58]

If scm.current_branch() had problem we should fix it instead of fixing it here.

We also need to fix another place calling current_branch() in this file.

[joelo, 2015/07/16 21:48:48]

Done.

             if old_branch_name == "HEAD":
                 # If HEAD is detached use commit SHA instead.
                 old_branch_name = tool.executive.run_command(["git", "rev-parse", "HEAD"])
             tool.scm().delete_branch(self.AUTO_REBASELINE_BRANCH_NAME)
             tool.scm().create_clean_branch(self.AUTO_REBASELINE_BRANCH_NAME)
 
             # If the tests are passing everywhere, then this list will be empty. We don't need
             # to rebaseline, but we'll still need to update TestExpectations.
             if test_prefix_list:
                 self._rebaseline(options, test_prefix_list)
@@ skipping 94 matching lines @@
             self._tool.scm().checkout_branch(old_branch_name)
         else:
             self._log_queue.put(self.QUIT_LOG)
         log_thread.join()
 
     def execute(self, options, args, tool):
         self._verbose = options.verbose
         while True:
             self._do_one_rebaseline()
             time.sleep(self.SLEEP_TIME_IN_SECONDS)