Roll src/third_party/pdfium/ aafdc153a..3e3a78b68 (4 commits)

https://pdfium.googlesource.com/pdfium.git/+log/aafdc153a2b7..3e3a78b68c31

$ git log aafdc153a..3e3a78b68 --date=short --no-merges --format='%ad %ae %s'
2017-09-13 art-snake Improve readability for CPDF_LinearizedHeader.
2017-10-04 hnakashima Fix UAF in SetVisible().
2017-10-02 art-snake Unify parsing of cross ref table v4.
2017-10-02 art-snake Simplify CPDF_DataAvail::ParseIndirectObjectAt

Created with:
  roll-dep src/third_party/pdfium


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: I581e223cbaa4d2fc0e2410fd567fdad0d91ff96a
Reviewed-on: https://chromium-review.googlesource.com/699644
Reviewed-by: <pdfium-deps-roller@chromium.org>
Commit-Queue: <pdfium-deps-roller@chromium.org>
Cr-Commit-Position: refs/heads/master@{#506483}

DEPS

@@ -69,7 +69,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling PDFium
   # and whatever else without interference from each other.
-  'pdfium_revision': 'aafdc153a2b7609968b315ca6c6900717f6d6c36',
+  'pdfium_revision': '3e3a78b68c31a5e7b27ef9ebd35f287603abe7fa',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling openmax_dl
   # and whatever else without interference from each other.