scrollable menu in drawer

http://stackoverflow.com/questions/27500112/polymer-core-scaffold-nav-core-menu-does-not-scroll

HTML

<link rel="import" href="http://www.polymer-project.org/0.5/components/polymer/polymer.html">
<link rel="import" href="http://www.polymer-project.org/0.5/components/paper-elements/paper-elements.html">
<link rel="import" href="http://www.polymer-project.org/0.5/components/core-elements/core-elements.html">

<polymer-element name="my-element" constructor="" attributes="">
    <template>
        <core-scaffold id="scaffold">
            <core-header-panel navigation flex mode="seamed">
                    <core-toolbar>
                        <div>Menu</div>
                    </core-toolbar>
                    <div class="content">
                        <core-menu valueattr="hash" selected="{{route}}" selectedModel="{{selectedPage}}"
                               on-core-select="{{menuItemSelected}}">
                            <template repeat="{{page, i in pages}}">
                                <paper-item hash="{{page.hash}}" noink style="color: #{{page.hash}}">
                                    <core-icon icon="label{{route != page.hash ? '-outline' : ''}}"></core-icon>
                                    <a href="#{{page.hash}}">{{page.label}}</a>
                                </paper-item>
                            </template>
                        </core-menu>                        
                    </div>
            </core-header-panel>
            <div tool>Title</div>
            <div>Main content goes here...</div>
        </core-scaffold>
    </template>
    <script>
        Polymer('my-element', {
            pages: [{label: '1', hash: "D6E3F2"},
                {label: '2', hash: "D6E3F2"},
                {label: '3', hash: "D6E3F2"},
                {label: '4', hash: "D6E3F2"},
                {label: '5', hash: "D6E3F2"},
                {label: '6', hash: "D6E3F2"},
                {label: '7', hash: "D6E3F2"},
                {label: '8', hash: "D6E3F2"},
                {label: '9', hash: "D6E3F2"},
               ...