XFA: merge patch from issue 801913002 and 804463003

Simplify PDFium by removing code that's not used in the open source repo.

-remove parameter from FPDF_InitLibrary
-remove a bunch of ifdefs that are unused

Fix build after previous commit.

TBR=tsepez@chromium.org
BUG=

Review URL: https://codereview.chromium.org/809513002
52 files changed