You can define document.readyinside the function, and it will work when called if it is already ready, for example:
google.load("visualization", "1", {packages:["linechart","table","piechart"]});
google.setOnLoadCallback(myLoad);
function myLoad() {
drawGraph();
$(document).ready(function() {
});
}
It should be noted here that you may not need document.ready at all, you can simply paste the contents into the same function.
drawGraph(); .ready().