paper-progress causes scrolling frame drops (w/ core-animated-pages)

[offthegrass]

I found paper-progress to be the cause of this scroll 'lag' bug in core-animated-pages:

googlearchive/core-animated-pages#48 (comment)

for me, it only happens in chrome for android.

I made a noscript version of paper-progress as I didn't require the animation:

<polymer-element name="progress-bar" noscript attributes="progress">
    <template>
        <style>
            :host {
                display: inline-block;
                width: 100%;
                height: 4px;
            }

            .container {
                position: relative;
                height: 100%;
                background-color: transparent;
                overflow: hidden;
            }
            .bar {
                width: 100%;
                height: 2px;
                margin:1px 0;
                background: #000;
            }
            .progress {
                height: 4px;
                width: {{progress}};
                background: #fff;
            }
        </style>
        <div class="container" flex layout horizontal>
            <div class="bar" fit></div>
            <div class="progress" fit></div>
        </div>
    </template>
</polymer-element>

this fixed the issue, so it's potentially a clash between the paper-progress animation and animated-pages (although I haven't tested it w/ core-pages etc.)