The window is finally just the window

In every browser, the window (the global object a page's scripts live in) and the document (the page itself) are two different things. In our engine they were one and the same, so asking the window for a web feature could hand back a piece of the page instead: the tool sites use to build and read web addresses, window.URL, came back as the page's own address, and code that relies on it failed. The window is now its own object, exactly as in the reference browser. Everything the page listens for, scrolling and the window's own properties work as before; we checked twelve real sites against the reference browser and none moved for the worse.