Roll src/third_party/pdfium/ 41d6bbe3d..38fd84428 (1 commit).

https://pdfium.googlesource.com/pdfium.git/+log/41d6bbe3d413..38fd84428a1e

$ git log 41d6bbe3d..38fd84428 --date=short --no-merges --format='%ad %ae %s'
2016-09-15 dsinclair Rename dictionary set and get methods

TBR=dsinclair@chromium.org

Review-Url: https://codereview.chromium.org/2339523005
Cr-Commit-Position: refs/heads/master@{#418920}

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': '41d6bbe3d413e7854be89142b70c42a89e315cba',
+  'pdfium_revision': '38fd84428a1ea007a043be0b7d9b289e47aa5da0',
   # 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.