Ability to make a Viewport become Game Camera at specified resolutions

Unity has this cool feature where a viewport can become the main camera view at specified resolutions.
Basically the viewport can toggle between level/scene view as it is already or Game Camera view. The Viewport gets a dropdown list box
at the top of it that allows you to select preset named resolutions for example iPad Landscape 1024x768 etc. There would also be
an option to add, modify and delete entries in this list.

The Viewport when in Game Camera mode is cropped to the exact pixel size based on this setting. Allowing you to have a WYSIWYG
as it will look on the target device. It’s a great tool for checking you have HUD stuff anchored correctly at all resolutions the target might have.