designer
<link rel="import" href="../google-map/google-map.html">
<polymer-element name="my-element">
<template>
<style>
:host {
position: absolute;
width: 100%;
height: 100%;
box-sizing: border-box;
top: 0px;
left: 0px;
background-color: rgb(255, 255, 255);
}
#google_map {
width: 100%;
height: 100%;
position: absolute;
left: 0px;
top: 0px;
}
</style>
<google-map showcentermarker id="google_map" horizontal layout center></google-map>
</template>
<script>
Polymer('my-element', {
});
</script>
</polymer-element>