Roll src/third_party/pdfium/ 4d29e78fc..98c6c15ab (1 commit).

https://pdfium.googlesource.com/pdfium.git/+log/4d29e78fc802..98c6c15abfec

$ git log 4d29e78fc..98c6c15ab --date=short --no-merges --format='%ad %ae %s'
2016-10-04 tsepez Fix ownership when making a private annot dictionary into a shared one.

TBR=dsinclair@chromium.org

Review-Url: https://codereview.chromium.org/2389413002
Cr-Commit-Position: refs/heads/master@{#423055}

DEPS

@@ -63,7 +63,7 @@ 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': '4d29e78fc80285d222f2bad916354e3db970d0cc',
+  'pdfium_revision': '98c6c15abfec45648d85c73e746f0cb109a8d35b',
   # 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.