Roll src/third_party/pdfium 9d3a62e82627..3681d5f8b5d7 (4 commits)

https://pdfium.googlesource.com/pdfium.git/+log/9d3a62e82627..3681d5f8b5d7

git log 9d3a62e82627..3681d5f8b5d7 --date=short --no-merges --format='%ad %ae %s'
2019-09-18 thestig@chromium.org Add CPDF_Array::GetBooleanAt().
2019-09-18 thestig@chromium.org Add yet another pixel test for invalid glyph ID.
2019-09-18 thestig@chromium.org Consistently declare operator=.
2019-09-18 thestig@chromium.org Sync third_party/freetype/OWNERS with Chromium's.

Created with:
  gclient setdep -r src/third_party/pdfium@3681d5f8b5d7

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/pdfium-autoroll
Please CC pdfium-deps-rolls@chromium.org on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

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

TBR=pdfium-deps-rolls@chromium.org

Bug: None
Change-Id: I6ed43661a048368120eb0d47def1cd02d0f9f29d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1811857Reviewed-by: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#697803}

DEPS

@@ -182,7 +182,7 @@ 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': '9d3a62e826277fa3e4864c8d4c7d49af2a0f3726',
+  'pdfium_revision': '3681d5f8b5d7978f3bd3123e1c97bb0b3de8e16d',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling BoringSSL
   # and whatever else without interference from each other.