Roll src/third_party/pdfium 88040c56ba07..488a283aa8a9 (2 commits)

https://pdfium.googlesource.com/pdfium.git/+log/88040c56ba07..488a283aa8a9

git log 88040c56ba07..488a283aa8a9 --date=short --first-parent --format='%ad %ae %s'
2020-04-28 thestig@chromium.org Simplify CPWL_Edit::DrawThisAppearance().
2020-04-28 thestig@chromium.org Fix a /Parent reference in xfa_pages_8_0.fragment.

Created with:
  gclient setdep -r src/third_party/pdfium@488a283aa8a9

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: None
Tbr: pdfium-deps-rolls@chromium.org
Change-Id: I43b25dbd6be89ce8e8580d57baf7d2916194e218
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2171496Reviewed-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@{#763589}

DEPS

@@ -195,7 +195,7 @@ 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': '88040c56ba075a1fc63585d7e47807d656b4130c',
+  'pdfium_revision': '488a283aa8a97aeb267c49482eaeea43bbcd9c97',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling BoringSSL
   # and whatever else without interference from each other.