GitLab

Add net/spdy/PRESUBMIT.py that checks files in net/spdy/core and
net/spdy/platform/api to make sure that classes, functions, and macros
that have been factored out into net/spdy/platform are only used in that
form in shared code.

Review-Url: https://codereview.chromium.org/2847613002
Cr-Commit-Position: refs/heads/master@{#467969}