
Fix bug in HTML5 history where you could set the same history token
twice.  There is a check to prevent this in non HTML5 history.

R=pupius
DELTA=4  (4 added, 0 deleted, 0 changed)


Revision created by MOE tool push_codebase.
MOE_MIGRATION=272836


yamadatomonori/closure-library,yamadatomonori/closure-library,yamadatomonori/closure-library