Roll PDFium from 184c9b9164b7 to d6055cbe1f06 (6 revisions)

https://pdfium.googlesource.com/pdfium.git/+log/184c9b9164b7..d6055cbe1f06

2020-09-30 nigi@chromium.org Add a pixel test for a link annotation that does not render.
2020-09-30 nigi@chromium.org Add a pixel test for a link annotation that does not render.
2020-09-29 tsepez@chromium.org Stop caching CXFA_FFWidgetHandler in CPDFSDK_Widget
2020-09-29 tsepez@chromium.org Bring XFA_RESOLVENODE_RS more in line with style guide.
2020-09-29 tsepez@chromium.org Avoid LSAN leak reports in XFA fuzzers
2020-09-29 thestig@chromium.org Fix nits with CPDF_CrossRefAvail member variables.

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/+doc/master/autoroll/README.md

Bug: chromium:1131837,chromium:1132607,chromium:237527
Tbr: pdfium-deps-rolls@chromium.org
Change-Id: Iccae44a9660c5858739a8dcc8c2f7ed3a5a888ac
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2436833Reviewed-by: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#811990}

DEPS

@@ -215,7 +215,7 @@ 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': '184c9b9164b7f92728e9277b47d3484a68bfa8c6',
+  'pdfium_revision': 'd6055cbe1f06a4f8acc172e53e4b2f14f2e057d6',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling BoringSSL
   # and whatever else without interference from each other.