See https://code.google.com/p/google-web-toolkit/issues/detail?id=624#c12 (this
was specifically for the FormPanel, but the underlying issue is the same)
A workaround seems to be to recreate a new Frame each time; not sure
whether the tricks from Closure would apply here.
On Wednesday,
I noticed that a certain page would appear many times in the 'go back'
history tokens. After some digging I found out that the cause is the class
'Frame', specifically every time I change the URL like this:
videoFrame.setUrl(url);
the tokens would increase with the same current page! Which is
