[SPDY] Remove references to obsolete SPDY versions SPDY/1 and SPDY/2.1
Remove them from NextProto and AlternateProtocol enums.
Add constants for minimum/maximum/number of valid AlternateProtocol
enum values and use that consistently.
Take care of TODOs to use kProtoSPDYMinimumVersion instead of
kProtoSPDY2 (since they're now one and the same).
BUG=303957
R=rtenneti@chromium.org
Review URL: https://codereview.chromium.org/25956002
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227043 0039d316-1c4b-4281-b951-d872f2087c98
17 files changed
