Docserver: Add commit history and _reset_commit servlet

chrome/common/extensions/docs/server2/handler.py

Index: chrome/common/extensions/docs/server2/handler.py
diff --git a/chrome/common/extensions/docs/server2/handler.py b/chrome/common/extensions/docs/server2/handler.py
index a0e044e753aab96ad34bc124736999020b42f372..5b02a392a5336986c02030aead62210501229df2 100644
--- a/chrome/common/extensions/docs/server2/handler.py
+++ b/chrome/common/extensions/docs/server2/handler.py
@@ -60,12 +60,31 @@ class _QueryCommitServlet(Servlet):
     return Response.Ok(commit_tracker.Get(self._request.path).Get())
 
 
+class _ResetCommitServlet(Servlet):
+  '''Writes a new commit ID to the commit cache. For example:
+
+  /_reset_commit/master/123456
+
+  will reset the 'master' commit ID to '123456'.
+  '''
+  def __init__(self, request):
+    Servlet.__init__(self, request)
+
+  def Get(self):
+    object_store_creator = ObjectStoreCreator(start_empty=False)
+    commit_tracker = CommitTracker(object_store_creator)
+    commit_name, commit_id = self._request.path.split('/')

[not at google - send to devlin, 2014/11/18 23:05:48]

Is there some kind of validation that you can do on the commit ID? It's pretty
scary just allowing the commit ID to be set arbitrarily.

+    commit_tracker.Set(commit_name, commit_id).Get()
+    return Response.Ok('Done.')
+
+
 _SERVLETS = {
   'cron': CronServlet,
   'enqueue': _EnqueueServlet,
   'patch': PatchServlet,
   'query_commit': _QueryCommitServlet,
   'refresh': RefreshServlet,
+  'reset_commit': _ResetCommitServlet,
   'test': TestServlet,
 }