It seems that blink/webkit browsers at least will leak memory when using
input[type=password] inputs. This only affects us during testing as we
'refresh' the ember app ~1000 times without actually refreshing
the browser. This means references to these HTML input elements mount
up now that every single page/test has an input[password] on it.
Following this change our memory usage during testing seems to have
reduced by as much as 75%.
During normal usage the single password element is only added to the
page once per login/logout.
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