Roll src/third_party/pdfium/ 917d24852..3f4111fbf (1 commit).

https://pdfium.googlesource.com/pdfium.git/+log/917d24852841..3f4111fbff12

$ git log 917d24852..3f4111fbf --date=short --no-merges --format='%ad %ae %s'
2016-09-23 tsepez Make CPDF_Font::Create() return a std::unique_ptr.

TBR=dsinclair@chromium.org

Review-Url: https://codereview.chromium.org/2361423002
Cr-Commit-Position: refs/heads/master@{#420618}

DEPS

@@ -63,7 +63,7 @@ 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': '917d24852841f4919f418076c0277d2742f961ca',
+  'pdfium_revision': '3f4111fbff1233de9f5c67eda433bee0f5f88c4e',
   # 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.