Merge to XFA: Tidy up JS_Object.h and JS_Object.cpp.

(cherry picked from commit b0b1a8bd45ed72e4fd22f5f0a394b7897ae573c7)
Original Review URL: https://codereview.chromium.org/1293673003 .

TBR=thestig@chromium.org

Review URL: https://codereview.chromium.org/1292283002 .
2 files changed