I've used this. Add a script reference to jquery on the Report.aspx page. Use the following to link up JQuery to the microsoft events. Used a little bit of Eric's suggestion for setting the overflow.
$(document).ready(function () {
if (navigator.userAgent.toLowerCase().indexOf("webkit") >= 0) {
Sys.Application.add_init(function () {
var prm = Sys.WebForms.PageRequestManager.getInstance();
if (!prm.get_isInAsyncPostBack()) {
prm.add_endRequest(function () {
var divs = $('table[id*=_fixedTable] > tbody > tr:last > td:last > div')
divs.each(function (idx, element) {
$(element).css('overflow', 'visible');
});
});
}
});
}
});