Roll src/third_party/pdfium/ ab3909796..de7c9620c (1 commit)

https://pdfium.googlesource.com/pdfium.git/+log/ab3909796cf2..de7c9620c374

$ git log ab3909796..de7c9620c --date=short --no-merges --format='%ad %ae %s'
2017-08-01 art-snake Prevent use of null pFileRead in CPDF_DataAvail.

Created with:
  roll-dep src/third_party/pdfium


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

Change-Id: Ifbf8ecee9c19109874bb2d0758e547bd4195f9f2
Reviewed-on: https://chromium-review.googlesource.com/595867
Reviewed-by: <pdfium-deps-roller@chromium.org>
Commit-Queue: <pdfium-deps-roller@chromium.org>
Cr-Commit-Position: refs/heads/master@{#490966}

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': 'ab3909796cf2e9fa192040bcd7cb9da7bb3328a5',
+  'pdfium_revision': 'de7c9620c37486413e1f7db4567b4b0cea6a857f',
   # 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.