Roll PDFium from 6069b8345ecb to 89b8527eceaf (12 revisions)

https://pdfium.googlesource.com/pdfium.git/+log/6069b8345ecb..89b8527eceaf

2020-06-26 thestig@chromium.org Remove Mac-specific includes from fx_system.h.
2020-06-26 thestig@chromium.org Remove unused header from fx_system.h.
2020-06-25 thestig@chromium.org Clean up star drawing code.
2020-06-25 tsepez@chromium.org Dismiss exceptions while setting properties/elements from JS handlers.
2020-06-25 vmiklos@collabora.co.uk Add FPDF_GetSignatureCount() API
2020-06-25 thestig@chromium.org Do one assignment per line in CXFA_Rectangle.
2020-06-25 thestig@chromium.org Fix some nits in string tests.
2020-06-25 thestig@chromium.org Test invalid arguments for some FPDFLink_* APIs.
2020-06-25 thestig@chromium.org Remove PRIuS define from fx_system.h.
2020-06-25 thestig@chromium.org Get rid of _FX_PLATFORM_APPLE_.
2020-06-25 thestig@chromium.org Get rid of _FX_PLATFORM_WINDOWS_.
2020-06-25 thestig@chromium.org Split tiling pattern rendering code into its own file.

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:1098213
Tbr: pdfium-deps-rolls@chromium.org
Change-Id: I73703255550202f21093b55c1b8e91875791dd78
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2269838
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Reviewed-by: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#782884}

DEPS

@@ -208,7 +208,7 @@ 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': '6069b8345ecb67c0ef78c1533cb321f5b3dd9244',
+  'pdfium_revision': '89b8527eceaf5ee25924047e329704fd79e2f925',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling BoringSSL
   # and whatever else without interference from each other.