Re-land: Update json_schema_compiler to handle the Automation extension API

tools/json_schema_compiler/model.py

 # Copyright (c) 2012 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.
 
 import os.path
 
 from json_parse import OrderedDict
 from memoize import memoize
 
 
@@ skipping 165 matching lines @@
                parent,
                name,
                json,
                namespace,
                origin):
     self.name = name
     self.namespace = namespace
     self.simple_name = _StripNamespace(self.name, namespace)
     self.unix_name = UnixName(self.name)
     self.description = json.get('description', None)
+    self.jsexterns = json.get('jsexterns', None)
     self.origin = origin
     self.parent = parent
     self.instance_of = json.get('isInstanceOf', None)
 
     # TODO(kalman): Only objects need functions/events/properties, but callers
     # assume that all types have them. Fix this.
     self.functions = _GetFunctions(self, json, namespace)
     self.events = _GetEvents(self, json, namespace)
     self.properties = _GetProperties(self, json, namespace, origin)
 
@@ skipping 114 matching lines @@
     self.supports_listeners = options.get('supportsListeners', True)
     self.supports_rules = options.get('supportsRules', False)
     self.supports_dom = options.get('supportsDom', False)
 
     def GeneratePropertyFromParam(p):
       return Property(self, p['name'], p, namespace, origin)
 
     self.filters = [GeneratePropertyFromParam(filter_instance)
                     for filter_instance in json.get('filters', [])]
     callback_param = None
-    for param in json.get('parameters', []):
-      if param.get('type') == 'function':
+    params = json.get('parameters', [])
+    for i, param in enumerate(params):
+      if param.get('type') == 'function' and i == len(params) - 1:
         if callback_param:
           # No ParseException because the webstore has this.
           # Instead, pretend all intermediate callbacks are properties.
           self.params.append(GeneratePropertyFromParam(callback_param))
         callback_param = param
       else:
         self.params.append(GeneratePropertyFromParam(param))
 
     if callback_param:
       self.callback = Function(self,
@@ skipping 276 matching lines @@
   # Sanity check: platforms should not be an empty list.
   if not json['platforms']:
     raise ValueError('"platforms" cannot be an empty list')
   platforms = []
   for platform_name in json['platforms']:
     for platform_enum in _Enum.GetAll(Platforms):
       if platform_name == platform_enum.name:
         platforms.append(platform_enum)
         break
   return platforms