Refactoring GLView for desktop platforms, and adding protected method `updateDesignResolutionSize` for GLViewProtocol class.
Compilation error fixes for linux port (clang compiler).
Tab -> 4 spaces, remove unused spaces.
updateDesignResolution -> updateDesignResolutionSize.
Tab -> 4 spaces, remove unused spaces for CCGLView.h
Merge pull request #5616 from dumganhar/glview-refactor

Refactoring GLView for desktop platforms, and adding protected method `updateDesignResolutionSize` for GLViewProtocol class.