Dynamically generate a heading for Extension Docs API pages

chrome/common/extensions/api/sync_file_system.idl

Index: chrome/common/extensions/api/sync_file_system.idl
diff --git a/chrome/common/extensions/api/sync_file_system.idl b/chrome/common/extensions/api/sync_file_system.idl
index c772c7090672da2b623c3e5e96a425d47fc774a0..3be2dce371c63686ca10680d11bfab03d7a8502d 100644
--- a/chrome/common/extensions/api/sync_file_system.idl
+++ b/chrome/common/extensions/api/sync_file_system.idl
@@ -2,6 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// Use the <code>chrome.syncFileSystem</code> API to save and synchronize data
+// on Google Drive. This API is NOT for accessing arbitrary user docs stored in
+// Google Drive. It provides app-speicif syncable storage for offline and
+// caching usage so that the same data can be available across different
+// clients. Read
+// <a href="http://developer.chrome.com/trunk/apps/app_storage.html">Manage
+// Data</a> for more on using this API.
+
+[availability=dev]
 namespace syncFileSystem {
   enum SyncAction {
     added, updated, deleted