Refactor WPT Export to ensure only one PR in flight at a time

third_party/WebKit/Tools/Scripts/webkitpy/w3c/github.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 base64
-import json
-import httplib2
-import logging
-
-_log = logging.getLogger(__name__)
-
-
-class GitHub(object):
-
-    def __init__(self, host):
-        self.host = host
-        self.user = self.host.environ.get('GH_USER')
-        self.token = self.host.environ.get('GH_TOKEN')
-
-        assert self.user and self.token, 'must have GH_USER and GH_TOKEN env vars'
-
-    def auth_token(self):
-        return base64.encodestring('{}:{}'.format(self.user, self.token))
-
-    def create_pr(self, local_branch_name, desc_title, body):
-        """Creates a PR on GitHub.
-
-        API doc: https://developer.github.com/v3/pulls/#create-a-pull-request
-
-        Returns:
-            A raw response object if successful, None if not.
-        """
-        assert local_branch_name
-        assert desc_title
-        assert body
-
-        pr_branch_name = '{}:{}'.format(self.user, local_branch_name)
-
-        # TODO(jeffcarp): add HTTP to Host and use that here
-        conn = httplib2.Http()
-        headers = {
-            "Accept": "application/vnd.github.v3+json",
-            "Authorization": "Basic " + self.auth_token()
-        }
-        body = {
-            "title": desc_title,
-            "body": body,
-            "head": pr_branch_name,
-            "base": "master"
-        }
-        resp, content = conn.request("https://api.github.com/repos/w3c/web-platform-tests/pulls",
-                                     "POST", body=json.JSONEncoder().encode(body), headers=headers)
-        _log.info("GitHub response: %s", content)
-        if resp["status"] != "201":
-            return None
-        return json.loads(content)