Remove OverloadSetAdapter.

Despite potential promise of code reuse, the effective overload
set algorithm isn't useful for C++-based bindings: the primary
purpose of the algorithm is to build a set that is later used
by the overload resolution algorithm:
https://heycam.github.io/webidl/#dfn-overload-resolution-algorithm

The purpose of this algorithm is to identify the overloaded
operation based on the arguments given. In case of C++,
the compiler does the work of identification and the task is
diminished to generating sufficient number of overloads
to express the intent in WebIDL.

That work is something that is more efficiently done with a
different algorithm.

Also added another unit test based on the spec example.

R=bashi@chromium.org,yukishiino@chromium.org
BUG=683743

Review-Url: https://codereview.chromium.org/2756993003
Cr-Commit-Position: refs/heads/master@{#457997}
2 files changed