Roll src/third_party/pdfium/ 28bb2f2ff..dc566b0a7 (4 commits)

https://pdfium.googlesource.com/pdfium.git/+log/28bb2f2ffe75..dc566b0a76f9

$ git log 28bb2f2ff..dc566b0a7 --date=short --no-merges --format='%ad %ae %s'
2018-04-04 hnakashima Fix XFA caret blinking only while mouse moves.
2018-04-04 thestig Parse "yy" correctly for AFDate_FormatEx().
2018-04-04 dsinclair Decrease XML parser buffer size
2018-04-04 dsinclair [fwl] Restrict setting cursor outside text bounds

Created with:
  roll-dep src/third_party/pdfium
BUG=chromium:828561,chromium:436572,chromium:813195


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: I2515beeac588ea2d53d3caa6d92bae0165da4824
Reviewed-on: https://chromium-review.googlesource.com/996232Reviewed-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@{#548171}

DEPS

@@ -106,7 +106,7 @@ 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': '28bb2f2ffe751cf4142329e27238da52ae9f848b',
+  'pdfium_revision': 'dc566b0a76f9d2ad112c8cc35fa6dc8eaf942316',
   # 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.