This patch:

1. Removes the unecessary inheritance of ParserBaseTraits<Impl>
   in ParserBase<Impl>.
2. Flattens ParserBaseTraits<Impl> and renames it to
   ParserTypes<Impl>.  The Traits parameter/member is renamed to
   Types.
3. Removes unecessary v8::internal:: qualifications from parser
   types.

R=adamk@chromium.org, marja@chromium.org
BUG=
LOG=N

Review-Url: https://codereview.chromium.org/2279773002
Cr-Commit-Position: refs/heads/master@{#38927}