Make flakiness dashboard links to googlesource work post git migration.

appengine_module/test_results/handlers/redirector.py

Index: appengine_module/test_results/handlers/redirector.py
diff --git a/appengine_module/test_results/handlers/redirector.py b/appengine_module/test_results/handlers/redirector.py
new file mode 100644
index 0000000000000000000000000000000000000000..9fb62f78a18fae1dded6439f6c581622a6d88f5c
--- /dev/null
+++ b/appengine_module/test_results/handlers/redirector.py
@@ -0,0 +1,31 @@
+# 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.
+
+# TODO(ojan): Get rid of this one crrev.com supports this directly.
+
+import json
+import urllib2
+
+
+# This is just to make testing easier.
+def load_url(url):  # pragma: no cover
+  return urllib2.urlopen(url).read()
+
+
+def commit_position_to_hash(commit_position):
+  url = 'https://cr-rev.appspot.com/_ah/api/crrev/v1/redirect/%s' % (
+      commit_position)
+  return str(json.loads(load_url(url))['git_sha'])
+
+
+def url_from_commit_positions(start_commit_position, end_commit_position):
+  start = commit_position_to_hash(start_commit_position)
+  end = commit_position_to_hash(end_commit_position)
+  return ('https://chromium.googlesource.com/chromium/src/+log'
+      '/%s..%s?pretty=fuller' % (start, end))
+
+
+def get_googlesource_url(handler, *_args, **_kwargs):  # pragma: no cover
+  return url_from_commit_positions(handler.request.get('start'),
+      handler.request.get('end'))