Merge to XFA: Store object definition ID in each js_class.

Manual edits in JS_Define.h.

(cherry picked from commit f0a5b2803c09f3605dcd606e764ef604f0d2a8ea)
Original Review URL: https://codereview.chromium.org/1382263002 .

R=thestig@chromium.org

Review URL: https://codereview.chromium.org/1382683008 .
18 files changed