Roll src/third_party/pdfium/ cbdf92688..8384757b2 (2 commits)

https://pdfium.googlesource.com/pdfium.git/+log/cbdf926884c4..8384757b2b00

$ git log cbdf92688..8384757b2 --date=short --no-merges --format='%ad %ae %s'
2017-05-04 npm More cleanup in CFX_ScanlineCompositor
2017-05-03 tsepez CPDF_DataAvail: avoid reads into stack buffers.

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: If9eaedc5b536a85a9647e9b88d453a113444268b
Reviewed-on: https://chromium-review.googlesource.com/495869
Reviewed-by: <pdfium-deps-roller@chromium.org>
Commit-Queue: <pdfium-deps-roller@chromium.org>
Cr-Commit-Position: refs/heads/master@{#469347}

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': 'cbdf926884c4d96a84ff12293fd45b9ec95d5b93',
+  'pdfium_revision': '8384757b2b00f11971d588f6fbe3a8c9aa755151',
   # 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.