function proportionalSizeChanged (node, components, size) {
    var proportionalSize = size.getProportional();
    var x = proportionalSize[0];
    var y = proportionalSize[1];
    var z = proportionalSize[2];
    if (node.onProportionalSizeChange) node.onProportionalSizeChange(x, y, z);
    for (var i = 0, len = components.length ; i < len ; i++)
        if (components[i] && components[i].onProportionalSizeChange)
            components[i].onProportionalSizeChange(x, y, z);
    size.proportionalSizeChanged = false;
}
Private method to alert the node and components that the proportional size changed.

@method
@private

@param {Node} node Node to potentially call onProportionalSizeChange on
@param {Array} components a list of the nodes' components
@param {Size} size the size class for the Node

@return {undefined} undefined