Roll src/third_party/pdfium 21bceb888974..9f35145a1ed0 (15 commits)

https://pdfium.googlesource.com/pdfium.git/+log/21bceb888974..9f35145a1ed0

git log 21bceb888974..9f35145a1ed0 --date=short --first-parent --format='%ad %ae %s'
2020-05-19 thestig@chromium.org Replace remaining FX_ArraySize() usage with pdfium::size().
2020-05-18 tsepez@chromium.org Remove pdfium::MakeUnique()
2020-05-18 tsepez@chromium.org Remove stray includes of ptr_util.h
2020-05-18 tsepez@chromium.org Convert remaining pdfium::MakeUnique<> to std::make_unique<> in xfa
2020-05-18 thestig@chromium.org Update third_party/base/optional.h.
2020-05-18 tsepez@chromium.org Convert pdfium::MakeUnique<> to std::make_unique<> in fxfa
2020-05-18 tsepez@chromium.org Convert pdfium::MakeUnique<> to std::make_unique<> in testing
2020-05-18 tsepez@chromium.org Convert pdfium::MakeUnique<> to std::MakeUnique<> in fpdfdoc.
2020-05-18 thestig@chromium.org Replace FX_ArraySize() with pdfium::size() in fpdfapi.
2020-05-18 tsepez@chromium.org Convert pdfium::MakeUnique<> to std::make_unique<> in fxge
2020-05-18 tsepez@chromium.org Convert pdfium::MakeUnique<> to std::make_unique<> in fxcrt
2020-05-18 tsepez@chromium.org Convert pdfium::MakeUnique<> to std::make_unique<> in fxcodec
2020-05-18 tsepez@chromium.org Convert pdfium::MakeUnique<> to std::make_unique<> in fpdfapi
2020-05-18 tsepez@chromium.org Convert pdfium::MakeUnique<> to std::make_unique<> in fxbarcode
2020-05-18 thestig@chromium.org Replace FX_ArraySize() with pdfium::size() outside of core/.

Created with:
  gclient setdep -r src/third_party/pdfium@9f35145a1ed0

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

Bug: chromium:1435
Tbr: pdfium-deps-rolls@chromium.org
Change-Id: I259eca44111c5692312159c9e00138806315fdc2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2208208Reviewed-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@{#769972}

DEPS

@@ -198,7 +198,7 @@ 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': '21bceb8889742b67a56714e291e1f3becb2fc123',
+  'pdfium_revision': '9f35145a1ed0fce39c61a8bcca5f2ab5117f6e86',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling BoringSSL
   # and whatever else without interference from each other.