Avoid to use the method pointer to Callback<>::Run on gmock tests

This CL replaces a problematic method pointers to Callback::Run with
testing::CreateFunctor.

The method pointer to Callback::Run prevents to make it a template
method or to overload it for cleaner implementation.

Review-Url: https://codereview.chromium.org/2758713002
Cr-Commit-Position: refs/heads/master@{#458018}
5 files changed