Remove IPDFSDK_AnnotHandler interface.

It's pointless to have an abstract interface and its only concrete
implementation defined in the same header.  We can de-virtualize along
the way and get a small savings.

Rename CPDFSDK_BFAnnotHandler along the way, since its the only kind
of AnnotHandler, and I can't imagine what BF stands for.

R=thestig@chromium.org

Review URL: https://codereview.chromium.org/1313733013 .
2 files changed