add GCS support to docs server

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

 # Copyright 2013 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.
 
 from branch_utility import BranchUtility
 from compiled_file_system import CompiledFileSystem
 from environment import IsDevServer
 from github_file_system_provider import GithubFileSystemProvider
 from host_file_system_provider import HostFileSystemProvider
 from third_party.json_schema_compiler.memoize import memoize
 from render_servlet import RenderServlet
 from object_store_creator import ObjectStoreCreator
 from server_instance import ServerInstance
+from gcs_file_system_provider import CloudStorageFileSystemProvider
 
 class InstanceServletRenderServletDelegate(RenderServlet.Delegate):
   '''AppEngine instances should never need to call out to SVN. That should only
   ever be done by the cronjobs, which then write the result into DataStore,
   which is as far as instances look. To enable this, crons can pass a custom
   (presumably online) ServerInstance into Get().
 
   Why? SVN is slow and a bit flaky. Cronjobs failing is annoying but temporary.
   Instances failing affects users, and is really bad.
 
@@ skipping 14 matching lines @@
     # development it's annoying to have to run the cron job, so offline=False.
     host_file_system_provider = self._delegate.CreateHostFileSystemProvider(
         object_store_creator,
         offline=not IsDevServer())
     github_file_system_provider = self._delegate.CreateGithubFileSystemProvider(
         object_store_creator)
     return ServerInstance(object_store_creator,
                           CompiledFileSystem.Factory(object_store_creator),
                           branch_utility,
                           host_file_system_provider,
-                          github_file_system_provider)
+                          github_file_system_provider,
+                          CloudStorageFileSystemProvider(object_store_creator))
 
 class InstanceServlet(object):
   '''Servlet for running on normal AppEngine instances.
   Create this via GetConstructor() so that cache state can be shared amongst
   them via the memoizing Delegate.
   '''
   class Delegate(object):
     '''Allow runtime dependencies to be overriden for testing.
     '''
     def CreateBranchUtility(self, object_store_creator):
       return BranchUtility.Create(object_store_creator)
 
     def CreateHostFileSystemProvider(self, object_store_creator, **optargs):
       return HostFileSystemProvider(object_store_creator, **optargs)
 
     def CreateGithubFileSystemProvider(self, object_store_creator):
       return GithubFileSystemProvider(object_store_creator)
 
   @staticmethod
   def GetConstructor(delegate_for_test=None):
     render_servlet_delegate = InstanceServletRenderServletDelegate(
         delegate_for_test or InstanceServlet.Delegate())
     return lambda request: RenderServlet(request, render_servlet_delegate)
 
   # NOTE: if this were a real Servlet it would implement a Get() method, but
   # GetConstructor returns an appropriate lambda function (Request -> Servlet).