Merge to XFA:Fix heap use after free in CPDFSDK_Annot::GetPDFAnnot.

(cherry picked from commit 9241e5a43990859f6f9a94aaa2c488d0451039e3)
Original Review URL: https://codereview.chromium.org/1312313006 .

(cherry picked from commit 343dbb841f4c12e819932e2b66dd70f817337d97)
Original Review URL: https://codereview.chromium.org/1325533004 .

BUG=507316
TBR=thestig@chromium.org

Review URL: https://codereview.chromium.org/1332653002 .
6 files changed