Merge to XFA: Do not call into formfiller code with a NULL PageView.

BUG=537173
TBR=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1376093002 .

(cherry picked from commit ac67d4765a8ac36cd00c9fc8b6f2b80a3e1cff72)

Review URL: https://codereview.chromium.org/1378193006 .
3 files changed