Roll src/third_party/pdfium c6642beb8c78..9d3a62e82627 (4 commits)

https://pdfium.googlesource.com/pdfium.git/+log/c6642beb8c78..9d3a62e82627

git log c6642beb8c78..9d3a62e82627 --date=short --no-merges --format='%ad %ae %s'
2019-09-18 awscreen@chromium.org [FXJS] Use double precision when converting textboxes
2019-09-17 awscreen@chromium.org [FXCRT] Test StringTo{Float,Double} with byte and wide strings
2019-09-17 thestig@chromium.org Roll third_party/freetype/src/ 3de1b8d0b..99f23d6ff (2 commits)
2019-09-17 thestig@chromium.org Add helper methods for getting objects in CPDF_FormField.

Created with:
  gclient setdep -r src/third_party/pdfium@9d3a62e82627

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

TBR=pdfium-deps-rolls@chromium.org

Bug: chromium:611744,chromium:611744
Change-Id: I17d8271682de47d90a9a12cd8ea87f0336ba5c13
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1810008Reviewed-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@{#697468}

DEPS

@@ -182,7 +182,7 @@ 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': 'c6642beb8c78df9a7a85c2c431cde184a7e76ee5',
+  'pdfium_revision': '9d3a62e826277fa3e4864c8d4c7d49af2a0f3726',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling BoringSSL
   # and whatever else without interference from each other.