AudioStreamCallback should use references rather than pointers

[dturner]

No description provided.

[dturner]

Phil - Why were we doing this again?

[philburk]

I believe they are preferred when a parameter should never be null. Mikhail?

[mnaganov]

This what Google C++ style guide suggests: https://google.github.io/styleguide/cppguide.html#Reference_Arguments

References should be used for input parameters (and thus references need to be labelled "const"), unless a null pointer is a valid input parameter value.

Pointers are mostly used for output parameters.

[philburk]

We decided that because the stream must be modified then we cannot do a const reference. So closing this as Will Not Fix.