Dynamically generate a heading for Extension Docs API pages

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

Index: chrome/common/extensions/docs/server2/patch_servlet.py
diff --git a/chrome/common/extensions/docs/server2/patch_servlet.py b/chrome/common/extensions/docs/server2/patch_servlet.py
index 32e1f92e00d08fc4cabb4681649a46bae271d935..0146fcee2d51ab9be2018d40db4ebe071b585d47 100644
--- a/chrome/common/extensions/docs/server2/patch_servlet.py
+++ b/chrome/common/extensions/docs/server2/patch_servlet.py
@@ -30,10 +30,13 @@ class _PatchServletDelegate(RenderServlet.Delegate):
   def CreateServerInstanceForChannel(self, channel):
     base_object_store_creator = ObjectStoreCreator(channel,
                                                    start_empty=False)
+    branch_utility = self._delegate.CreateBranchUtility(
+        base_object_store_creator)
     # TODO(fj): Use OfflineFileSystem here once all json/idl files in api/
     # are pulled into data store by cron jobs.
     base_file_system = CachingFileSystem(
-        self._delegate.CreateHostFileSystemForBranch(channel),
+        self._delegate.CreateHostFileSystemForBranch(
+            branch_utility.GetChannelInfo(channel).branch),
         base_object_store_creator)
     base_compiled_fs_factory = CompiledFileSystem.Factory(
         base_file_system, base_object_store_creator)
@@ -53,13 +56,22 @@ class _PatchServletDelegate(RenderServlet.Delegate):
     compiled_fs_factory = ChainedCompiledFileSystem.Factory(
         [(patched_compiled_fs_factory, patched_file_system),
          (base_compiled_fs_factory, base_file_system)])
+
+    def create_file_system(version):
+      return CachingFileSystem(
+          self._delegate.CreateHostFileSystemForBranch(
+              branch_utility.GetBranchForVersion(version)),
+          base_object_store_creator)
+
     return ServerInstance(channel,
                           object_store_creator,
                           patched_file_system,
                           self._delegate.CreateAppSamplesFileSystem(
                               base_object_store_creator),
                           '/_patch/%s' % self._issue,
-                          compiled_fs_factory)
+                          compiled_fs_factory,
+                          branch_utility,
+                          create_file_system)
 
 class PatchServlet(Servlet):
   '''Servlet which renders patched docs.