Roll src/third_party/pdfium c9edc556eae1..db9976265161 (3 commits)

https://pdfium.googlesource.com/pdfium.git/+log/c9edc556eae1..db9976265161

git log c9edc556eae1..db9976265161 --date=short --no-merges --format='%ad %ae %s'
2019-08-06 thestig@chromium.org Remove code that checks GetSystemHandler() return value.
2019-08-06 tsepez@chromium.org Deduplicate pointers to widgets in pwl.
2019-08-06 thestig@chromium.org Simplify code in CPWL_EditCtrl::SetCursor().

Created with:
  gclient setdep -r src/third_party/pdfium@db9976265161

The AutoRoll server is located here: https://autoroll.skia.org/r/pdfium-autoroll

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.


TBR=pdfium-deps-rolls@chromium.org

Bug: None
Change-Id: Ibb6eff26cfcd25d8de279af96cb540ac271532fd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1738651Reviewed-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@{#684457}

DEPS

@@ -165,7 +165,7 @@ 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': 'c9edc556eae15379bd56a91829d12f088f7739bc',
+  'pdfium_revision': 'db997626516180fe0a22d7eba22a748acd1dfa10',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling BoringSSL
   # and whatever else without interference from each other.