Roll src/third_party/pdfium 784cc7b22b21..88040c56ba07 (6 commits)

https://pdfium.googlesource.com/pdfium.git/+log/784cc7b22b21..88040c56ba07

git log 784cc7b22b21..88040c56ba07 --date=short --first-parent --format='%ad %ae %s'
2020-04-28 tsepez@chromium.org Null check not needed for CFX_GEModule::GetFontMgr() return value.
2020-04-27 thestig@chromium.org Disable deflate TIFF support.
2020-04-27 thestig@chromium.org Replace BIT_INDEX_TO_BYTE and BIT_INDEX_TO_ALIGNED_BYTE macros.
2020-04-27 thestig@chromium.org Disable OJPEG style TIFF support.
2020-04-27 thestig@chromium.org Remove unnecessary fx_string.h usage.
2020-04-27 thestig@chromium.org Add a regression test for bad Type3 font glyphs.

Created with:
  gclient setdep -r src/third_party/pdfium@88040c56ba07

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:1371,chromium:966263
Tbr: pdfium-deps-rolls@chromium.org
Change-Id: I7f9e2e302b8e3dd96c125e8491f26c45d5bbd3a1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2170803Reviewed-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@{#763529}

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': '784cc7b22b215da7decce549876c1671d335f0f0',
+  'pdfium_revision': '88040c56ba075a1fc63585d7e47807d656b4130c',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling BoringSSL
   # and whatever else without interference from each other.