The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/977311fa0e0d3ff8edfbb4ccb5b11b21037e13f0

commit 977311fa0e0d3ff8edfbb4ccb5b11b21037e13f0
Author: rdevlin.cronin <rdevlin.cronin@chromium.org>
Date: Wed Aug 17 21:23:38 2016

[Extension DocServer] Update BranchUtility, README

BranchUtility uses Omaha Proxy's version history
(https://omahaproxy.appspot.com/history.json?channel=dev&os=win&json=1)
to get the set of versions to use, and raises an exception if one fails.
However, the version history isn't eternal, and only returns a limited
amount. Handle the gracefully and add an ugly hacky assert until we do
something better.

Also update the README instructions for showing the dev server.

BUG= 638731 

Review-Url: https://codereview.chromium.org/2250823003
Cr-Commit-Position: refs/heads/master@{#412641}

[modify] https://crrev.com/977311fa0e0d3ff8edfbb4ccb5b11b21037e13f0/chrome/common/extensions/docs/server2/README
[modify] https://crrev.com/977311fa0e0d3ff8edfbb4ccb5b11b21037e13f0/chrome/common/extensions/docs/server2/app.yaml
[modify] https://crrev.com/977311fa0e0d3ff8edfbb4ccb5b11b21037e13f0/chrome/common/extensions/docs/server2/branch_utility.py

Change pushed, docserver updated, live version seems stable.