MD Settings: Introduce CrScrollableBehavior

ui/webui/resources/cr_elements/compiled_resources2.gyp

 # Copyright 2014 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.
 {
   'targets': [
     {
       'target_name': 'cr_elements_resources',
       'type': 'none',
       'dependencies': [
         'cr_dialog/compiled_resources2.gyp:*',
         'cr_profile_avatar_selector/compiled_resources2.gyp:*',
         'cr_slider/compiled_resources2.gyp:*',
         'network/compiled_resources2.gyp:*',
         'policy/compiled_resources2.gyp:*',
       ],
     },
+    {
+      'target_name': 'cr_scrollable_behavior',
+      'dependencies': [
+        '<(DEPTH)/third_party/polymer/v1_0/components-chromium/iron-list/compiled_resources2.gyp:iron-list-extracted',
+      ],
+      'includes': ['../../../../third_party/closure_compiler/compile_js2.gypi'],
+    },
   ]
 }