Fix else-after-returns throughout pdfium.

Driven by CS search for
pcre:yes file:third_party/pdfium/ -file:pdfium/third_party/
\breturn\b[^;]*;\s*\n*\s*\}*\s*\n*\r*else

Note: Care is required to ensure the preceding block is not an else-if.

As usual, removed any tabs I saw.

R=thestig@chromium.org

Review URL: https://codereview.chromium.org/1243883003 .
78 files changed