Add access to direct write font proxy in pdf compositor service

Pdf compositor service needs to access direct write font proxy to
be able to use skia to draw properly on Windows. This CL move font
proxy init header to public so more processes (including ours)
can use it, also it adds font proxy initialization in pdf
compositor service.

TBR=thestig@chromium.org
BUG=455764

Change-Id: Ia7bf3c7804ae0fea671087a53cf177615ca4d59e
Reviewed-on: https://chromium-review.googlesource.com/685271
Commit-Queue: Wei Li <weili@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#506150}
12 files changed