Roll PDFium 461129e..2ba3dc7

      https://pdfium.googlesource.com/pdfium.git/+log/461129e..2ba3dc7

BUG=504658,603518

TEST=bots
TBR=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1893753002

Cr-Commit-Position: refs/heads/master@{#387739}