Merge to XFA: Cleanup JBig2_ArithIntDecoder.

TBR=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1359013003 .

(cherry picked from commit ce37d7347f1ab4c9fc1f48a137628da641bb4f14)

Review URL: https://codereview.chromium.org/1386473002 .
5 files changed