Roll src/third_party/pdfium/ 44bc1f818..988224309 (1 commit).

https://pdfium.googlesource.com/pdfium.git/+log/44bc1f818dd7..98822430907b

$ git log 44bc1f818..988224309 --date=short --no-merges --format='%ad %ae %s'
2017-01-11 tsepez Pass expose-gc flag to pdfium test programs.

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

If the roll is causing failures, see:
http://www.chromium.org/developers/tree-sheriffs/sheriff-details-chromium#TOC-Failures-due-to-DEPS-rolls

TBR=dsinclair@chromium.org

Review-Url: https://codereview.chromium.org/2622003003
Cr-Commit-Position: refs/heads/master@{#442904}

DEPS

@@ -64,7 +64,7 @@ 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': '44bc1f818dd791c2a5a81103be3853093fd934b3',
+  'pdfium_revision': '98822430907b603d671f8ade5f20723a0f8ecc03',
   # 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.