[danik.js]

Вероятно не самый лучший вариант..

<style>
.float{height: 20px;background: yellow}
.size{height:100px}
</style>
<div class="float"></div>
<script>
(function(){
var onDocumentClick = function() {
    setTimeout(function(){
        element.addEventListener('click', onElementClick);
    });
    document.removeEventListener('click', onDocumentClick);
    element.classList.remove('size');
};
var onElementClick = function() {
    setTimeout(function(){
        document.addEventListener('click', onDocumentClick);
    });
    element.removeEventListener('click', onElementClick);
    element.classList.add('size');
};

var element = document.querySelector('.float');
element.addEventListener('click', onElementClick);
})();
</script>