The motivation is that Chrome XBL stylesheets can be parsed under author
level, but we allow some event-state pseudo classes like
:-moz-handled-clicktoplay to be used.
Also synchronize the privilege of pseudo classes in
non_ts_pseudo_class_list.rs and nsCSSPseudoClassList.h (except :fullscreen).
MozReview-Commit-ID: 8fUjjC8hbQO
Implement range index with the Position enum on ServoUrl
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- [ ] These changes fix #__ (github issue number if applicable).
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r? @emilio
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Move the `check_and_scroll_fragment()` method into Document, make the
mothod set the fragment of url after navigation, and use the
`perform_a_scroll()` method to scroll rather than an individual
method. Also removes the broken `Window.fragment` fields.
