Web Replay: memoize nondeterministic attributes of the Screen interface

Web Replay: memoize nondeterministic attributes of the Screen interface
https://bugs.webkit.org/show_bug.cgi?id=131339

Reviewed by Timothy Hatcher.

.:

* ManualTests/inspector/replay-window-screen.html: Added.

Source/WebCore:

The values from the screen interface are nondeterministic. Since we can't
change the physical screen dimensions, instead memoize values of attributes.

Test: ManualTests/inspector/replay-window-screen.html

* page/Screen.idl: Add Nondeterministic attribute.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@166984 268f45cc-cd09-0410-ab3c-d52691b4dbfc