Roll src/third_party/pdfium/ c29fc707b..0ca160fbf (3 commits).

https://pdfium.googlesource.com/pdfium.git/+log/c29fc707b24b..0ca160fbf31a

$ git log c29fc707b..0ca160fbf --date=short --no-merges --format='%ad %ae %s'
2016-09-08 npm Delete unused methods in CPDF_Document
2016-09-08 dsinclair Fix CPDFSDK_PageView cleanup.
2016-09-08 jaepark Check whether the annotation content is empty using CFX_WideString.

BUG=645122

TBR=dsinclair@chromium.org

Review-Url: https://codereview.chromium.org/2319773004
Cr-Commit-Position: refs/heads/master@{#417423}

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': 'c29fc707b24b9528e41a242cfa298275708ffc76',
+  'pdfium_revision': '0ca160fbf31a7408df282823f7a3d4cbb5f386a1',
   # 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.