Roll src/third_party/pdfium/ 8f53f54a9..0a17fafd7 (6 commits).

https://pdfium.googlesource.com/pdfium.git/+log/8f53f54a9cca..0a17fafd723e

$ git log 8f53f54a9..0a17fafd7 --date=short --no-merges --format='%ad %ae %s'
2016-09-15 tonikitoo Use either /RECT or /QuadPoints for annotation coordinates, depending on /AP
2016-09-15 npm Use ToUnicode mapping even when unicode is 0.
2016-09-15 npm Deleted unused defintions and methods from PWL_FontMap
2016-09-15 dsinclair Cleanup CFX_SystemHandler.
2016-09-15 dsinclair Use safe math when rendering line segments in AGG.
2016-09-15 dsinclair Replace FX_UINT with unsigned int

BUG=647026

TBR=dsinclair@chromium.org

Review-Url: https://codereview.chromium.org/2342113002
Cr-Commit-Position: refs/heads/master@{#419003}

DEPS

@@ -60,7 +60,7 @@ 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': '8f53f54a9ccada2ea8651f2786f1bbee323f09b7',
+  'pdfium_revision': '0a17fafd723e8684d1deb4b5ceea58967a0154da',
   # 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.