third_party/WebKit/LayoutTests/plugins/webview-plugin-scroll.html

<!doctype HTML>
<embed id="plugin" type="application/x-plugin-placeholder-test"></embed>
<div style="height: 3000px"></div>
<style>
::-webkit-scrollbar {
    -webkit-appearance: none;
}
</style>
<script>
onload = function() {
    window.scrollBy(0, 50);
    if (window.testRunner) {
        window.testRunner.waitUntilDone();
        // Need to paint two frames in order to allow the plugin to properly load.
        // TODO(chrishtr): find out why and fix.
        requestAnimationFrame(function() {
            requestAnimationFrame(function() {
                requestAnimationFrame(function() {
                    window.testRunner.notifyDone();
                });
            });
        });
    }
}
</script>