Roll src/third_party/pdfium/ 131c0eb2e..56ec0818c (1 commit)

https://pdfium.googlesource.com/pdfium.git/+log/131c0eb2e34e..56ec0818c3ed

$ git log 131c0eb2e..56ec0818c --date=short --no-merges --format='%ad %ae %s'
2017-09-11 palmer Use the right allocate and free functions in OpenJPEG.

Created with:
  roll-dep src/third_party/pdfium
BUG=762374


Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, see:
http://www.chromium.org/developers/tree-sheriffs/sheriff-details-chromium#TOC-Failures-due-to-DEPS-rolls


TBR=dsinclair@chromium.org

Change-Id: Id0d43903dbc84611c3aaae9e28ca65896cf40de0
Reviewed-on: https://chromium-review.googlesource.com/660679
Reviewed-by: <pdfium-deps-roller@chromium.org>
Commit-Queue: <pdfium-deps-roller@chromium.org>
Cr-Commit-Position: refs/heads/master@{#501040}