Roll src/third_party/pdfium/ 7f472cd8a..86688dea3 (3 commits)

https://pdfium.googlesource.com/pdfium.git/+log/7f472cd8abe4..86688dea3b0d

$ git log 7f472cd8a..86688dea3 --date=short --no-merges --format='%ad %ae %s'
2018-05-22 thestig Make friend RetainPtr<T> statements consistently public.
2018-05-22 thestig Fix nits in fxjs.
2018-05-22 thestig Simplify CPDF_ShadingPattern::Validate().

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: I284bf7cc2464e552f0fadf8433244cd17bd81a72
Reviewed-on: https://chromium-review.googlesource.com/1069968Reviewed-by: pdfium-chromium-autoroll <pdfium-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Commit-Queue: pdfium-chromium-autoroll <pdfium-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#560954}

DEPS

@@ -120,7 +120,7 @@ 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': '7f472cd8abe48ffc59dee2a7e37f72e469ddfd7e',
+  'pdfium_revision': '86688dea3b0d30741a95fd15b5f9ee57b2ae86f1',
   # 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.