Add more test coverage to push-to-trunk script.

tools/push-to-trunk/common_includes.py

 #!/usr/bin/env python
 # Copyright 2013 the V8 project authors. 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
@@ skipping 49 matching lines @@
 
 def FileToText(file_name):
   with open(file_name) as f:
     return f.read()
 
 
 def MSub(rexp, replacement, text):
   return re.sub(rexp, replacement, text, flags=re.MULTILINE)
 
 
+def GetLastChangeLogEntries(change_log_file):
+  result = []
+  for line in LinesInFile(change_log_file):
+    if re.search(r"^\d{4}-\d{2}-\d{2}:", line) and result: break
+    result.append(line)
+  return "".join(result)
+
+
 # Some commands don't like the pipe, e.g. calling vi from within the script or
 # from subscripts like git cl upload.
 def Command(cmd, args="", prefix="", pipe=True):
   cmd_line = "%s %s %s" % (prefix, cmd, args)
   print "Command: %s" % cmd_line
   try:
     if pipe:
       return subprocess.check_output(cmd_line, shell=True)
     else:
       return subprocess.check_call(cmd_line, shell=True)
@@ skipping 200 matching lines @@
 class UploadStep(Step):
   def __init__(self):
     Step.__init__(self, "Upload for code review.")
 
   def RunStep(self):
     print "Please enter the email address of a V8 reviewer for your patch: ",
     reviewer = self.ReadLine()
     args = "cl upload -r \"%s\" --send-mail" % reviewer
     if self.Git(args,pipe=False) is None:
       self.Die("'git cl upload' failed, please try again.")