Roll src/third_party/pdfium/ 90e03b9b3..6453a67d8 (4 commits)

https://pdfium.googlesource.com/pdfium.git/+log/90e03b9b3f45..6453a67d84dc

$ git log 90e03b9b3..6453a67d8 --date=short --no-merges --format='%ad %ae %s'
2018-04-24 dsinclair Remove CFX_BlockBuffer
2018-04-24 hnakashima Fix edit text rendered with wrong offsets after deletion.
2018-04-24 dsinclair Cleanup CFX_XMLParser entity conversion
2018-04-24 hnakashima Fix caret moving to next line on click in multiline XFA edit.

Created with:
  roll-dep src/third_party/pdfium
BUG=chromium:835924,chromium:832293


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: I3b1032022230598dcb53c04384247169802053c9
Reviewed-on: https://chromium-review.googlesource.com/1024605
Commit-Queue: pdfium-chromium-autoroll <pdfium-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Reviewed-by: pdfium-chromium-autoroll <pdfium-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#553253}

DEPS

@@ -114,7 +114,7 @@ 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': '90e03b9b3f459e8812301b58ec0952b136f23a53',
+  'pdfium_revision': '6453a67d84dc321a5f28728e04929dc2ff35ff88',
   # 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.