Merge to XFA: Guard against null image data in CJBig2_GRRDProc.

Credit to karl at skomski.com for the initial version of the CL.

BUG=527174
TBR=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1305033006 .

(cherry picked from commit 89d8b4681ce98894a1ee1a6cf4bae77e00d28797)

Review URL: https://codereview.chromium.org/1331303002 .
4 files changed