Move everything unrelated to the frame tree out of Page and into Document or Window. Reduce the API surface of Page to a bare minimum to allow for easier future removal.

components/script/dom/htmlelement.rs

@@ -26,6 +26,7 @@ use dom::htmlmediaelement::HTMLMediaElementTypeId;
 use dom::htmltablecellelement::HTMLTableCellElementTypeId;
 use dom::node::{Node, NodeTypeId, window_from_node};
 use dom::virtualmethods::VirtualMethods;
+use dom::window::WindowHelpers;
 
 use util::str::DOMString;