[Findit] Fix redirect bug and update template for waterfall/culprit.

appengine/findit/common/http_client_appengine.py

 # 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.
 
 import json
 import logging
 
 from google.appengine.api import urlfetch
 
 from common import auth_util
 from common.retry_http_client import RetryHttpClient
 
 
 # TODO(katesonia): Move this to config.
 _INTERNAL_HOSTS_TO_SCOPES = {
     'https://chrome-internal.googlesource.com/': (
         'https://www.googleapis.com/auth/gerritcodereview'),
     'https://codereview.chromium.org/': (
         'https://www.googleapis.com/auth/userinfo.email'),
 }
 
 
 class HttpClientAppengine(RetryHttpClient):  # pragma: no cover
   """A http client for running on appengine."""
 
+  def __init__(self, follow_redirects=True, *args, **kwargs):
+    super(HttpClientAppengine, self).__init__(*args, **kwargs)
+    self.follow_redirects = follow_redirects
+
   def _ExpandAuthorizationHeaders(self, headers, scope):
     headers['Authorization'] = 'Bearer ' + auth_util.GetAuthToken(scope)
 
   def _ShouldLogError(self, status_code):
     if not self.no_error_logging_statuses:
       return True
     return status_code not in self.no_error_logging_statuses
 
   def _SendRequest(self, url, method, data, timeout, headers=None):
     # We wanted to validate certificate to avoid the man in the middle.
     if not headers:
       headers = {}
 
     # For google internal hosts, expand Oauth2.0 token to headers to authorize
     # the requests.
     for host, scope in _INTERNAL_HOSTS_TO_SCOPES.iteritems():
       if url.startswith(host):
         self._ExpandAuthorizationHeaders(headers, scope)
         logging.debug('Authorization header of scope %s was added for %s',
                       scope, url)
         break
 
     if method in (urlfetch.POST, urlfetch.PUT):
       result = urlfetch.fetch(
           url, payload=data, method=method, headers=headers, deadline=timeout,
-          follow_redirects=False, validate_certificate=True)
+          follow_redirects=self.follow_redirects, validate_certificate=True)
     else:
       result = urlfetch.fetch(
           url, headers=headers, deadline=timeout,
-          follow_redirects=False, validate_certificate=True)
+          follow_redirects=self.follow_redirects, validate_certificate=True)
 
     if (result.status_code != 200 and self._ShouldLogError(result.status_code)):
       logging.error('Request to %s resulted in %d, headers:%s', url,
                     result.status_code, json.dumps(result.headers.items()))
 
     return result.status_code, result.content
 
   def _Get(self, url, timeout, headers):
     return self._SendRequest(url, urlfetch.GET, None, timeout, headers)
 
   def _Post(self, url, data, timeout, headers):
     return self._SendRequest(url, urlfetch.POST, data, timeout, headers)
 
   def _Put(self, url, data, timeout, headers):
     return self._SendRequest(url, urlfetch.PUT, data, timeout, headers)