Roll src/third_party/pdfium/ e9988dd65..a0ff010a3 (1 commit).

https://pdfium.googlesource.com/pdfium.git/+log/e9988dd65e74..a0ff010a380c

$ git log e9988dd65..a0ff010a3 --date=short --no-merges --format='%ad %ae %s'
2016-09-19 stackexploit Avoid nullptr access in sycc422_to_rgb and sycc420_to_rgb

BUG=648127

TBR=dsinclair@chromium.org

Review-Url: https://codereview.chromium.org/2351703002
Cr-Commit-Position: refs/heads/master@{#419452}

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': 'e9988dd65e743a9b70482aa3007cec2c9789f679',
+  'pdfium_revision': 'a0ff010a380c98d2092ff849ffc2f672e87fc799',
   # 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.