Roll src/third_party/pdfium/ 4d4731c62..9b85f4ba6 (8 commits)

https://pdfium.googlesource.com/pdfium.git/+log/4d4731c620ea..9b85f4ba6fdd

$ git log 4d4731c62..9b85f4ba6 --date=short --no-merges --format='%ad %ae %s'
2018-01-23 dsinclair Merge CXFA_WidgetAcc into CXFA_Node
2018-01-23 dsinclair Remove CXFA_WidgetAcc from CXFA_FFDocView methods
2018-01-23 dsinclair Cleanup CXFA_FFDocView header
2018-01-23 dsinclair Remove unused CXFA_FFDocView::ProcessWidgetEvent
2018-01-23 dsinclair Remove CXFA_FFDocView::GetWidgetAccByName
2018-01-23 dsinclair Use accessor for WidgetAcc
2018-01-23 dsinclair Convert CXFA_WidgetAccIterator to CXFA_ReadyNodeIterator
2018-01-23 dsinclair Remove CXFA_WidgetAcc from CXFA_FFField::CalculateNode

Created with:
  roll-dep src/third_party/pdfium


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

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=dsinclair@chromium.org

Change-Id: I9e5c17b55282293199630ec5badd69659f2b552a
Reviewed-on: https://chromium-review.googlesource.com/881825
Reviewed-by: <pdfium-deps-roller@chromium.org>
Commit-Queue: <pdfium-deps-roller@chromium.org>
Cr-Commit-Position: refs/heads/master@{#531383}

DEPS

@@ -103,7 +103,7 @@ 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': '4d4731c620ea1fa95c07f8855f84d28c78090119',
+  'pdfium_revision': '9b85f4ba6fdd86c488498003a2db5854d4ece036',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling openmax_dl
   # and whatever else without interference from each other.