Fix some closure compilation issues 8n order to update compiler.jar

third_party/closure_compiler/checker.py

 #!/usr/bin/python
 # Copyright 2014 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.
 
 """Runs Closure compiler on a JavaScript file to check for errors."""
 
 import argparse
 import os
 import re
@@ skipping 120 matching lines @@
     real_file = self._processor.get_file_from_line(match.group(1))
     return "%s:%d" % (os.path.abspath(real_file.file), real_file.line_number)
 
   def _fix_up_error(self, error):
     """Filter out irrelevant errors or fix line numbers.
 
     Args:
         error: A Closure compiler error (2 line string with error and source).
 
     Return:
-        The fixed up erorr string (blank if it should be ignored).
+        The fixed up error string (blank if it should be ignored).
     """
     if " first declared in " in error:
       # Ignore "Variable x first declared in /same/file".
       return ""
 
     expanded_file = self._expanded_file
     fixed = re.sub("%s:(\d+)" % expanded_file, self._fix_line_number, error)
     return fixed.replace(expanded_file, os.path.abspath(self._file_arg))
 
   def _format_errors(self, errors):
@@ skipping 62 matching lines @@
     errors = stderr.strip().split("\n\n")
 
     # Filter out false-positive promise chain errors.
     # See https://github.com/google/closure-compiler/issues/715 for details.
     errors = self._error_filter.filter(errors);
 
     self._debug("Summary: %s" % errors.pop())
 
     output = self._format_errors(map(self._fix_up_error, errors))
     if errors:
-      self._error("Error in: %s%s" % (source_file, "\n" + output if output else ""))
+      prefix = "\n" if output else ""
+      self._error("Error in: %s%s%s" % (source_file, prefix, output))
     elif output:
       self._debug("Output: %s" % output)
 
     self._clean_up()
 
     return bool(errors), output
 
 
 if __name__ == "__main__":
   parser = argparse.ArgumentParser(
@@ skipping 16 matching lines @@
     exit, _ = checker.check(source, depends=depends, externs=externs)
     if exit != 0:
       sys.exit(exit)
 
     if opts.out_file:
       out_dir = os.path.dirname(opts.out_file)
       if not os.path.exists(out_dir):
         os.makedirs(out_dir)
       # TODO(dbeam): write compiled file to |opts.out_file|.
       open(opts.out_file, "w").write("")