Roll pdfium 76b01042:8840ec9b

Pick up:
8840ec9b "Remove unused function"

BUG=82385, 558413
R=thestig@chromium.org
TBR=thestig

Review URL: https://codereview.chromium.org/1459163004 .

Cr-Commit-Position: refs/heads/master@{#360680}
1 file changed