Roll src/third_party/pdfium d15d718e8d5e..c80274e041d6 (3 commits)

https://pdfium.googlesource.com/pdfium.git/+log/d15d718e8d5e..c80274e041d6

git log d15d718e8d5e..c80274e041d6 --date=short --first-parent --format='%ad %ae %s'
2020-02-19 tsepez@chromium.org Remove CFX_CSSSyntaxParser::m_iTextDataLen
2020-02-19 tsepez@chromium.org Remove some dead code from CFX_CSSSyntaxParser
2020-02-19 tsepez@chromium.org Prefer retaining layout item in CXFA_FFField::OnChar().

Created with:
  gclient setdep -r src/third_party/pdfium@c80274e041d6

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:1052651
Tbr: pdfium-deps-rolls@chromium.org
Change-Id: I0d696bae9b4f458409fabcee472c4c4ee87d4f93
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2065406Reviewed-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@{#742928}

DEPS

@@ -191,7 +191,7 @@ 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': 'd15d718e8d5e8d664454625f2b0c51ed71a2b10e',
+  'pdfium_revision': 'c80274e041d6e22de8fd420f3d688905d5d02692',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling BoringSSL
   # and whatever else without interference from each other.