glide: Revert win32 code path to upstream version.

This has no affect on the Android implementation, but makes it easier
to diff and sync with upstream.

Recommend submitting the win32 streamlining as a separate pull request
to upstream.
glide: Merge upstream changes, tweak cosmetics to reduce upstream diff.

No functional changes.  Switched comment style from // to /* */ in some
areas to reduce diff and make synchronizations with upstream easier.

Based on upstream changeset 78 (8e0edcb92860).