No functional changes. Code is ported to C++ with additional cleanups to
the logic and variable names.
Differential Revision: https://developer.blender.org/D9741
See https://developer.blender.org/D9499.
It's odd to include a C++ header (".hh") in C code, we should avoid that. All
of the Outliner code should be moved to C++, I don't expect this C header to
stay for long.
See https://developer.blender.org/D9499.
"View" leads to weird names like `TreeViewViewLayer` and after all they are
specific to what we call a "display mode", so "display" is more appropriate.
Also add, update and correct comments.