This patch will allow the user to select the EEVEE renderpass to be shown in the viewport by default the combined pass will be shown. Limitations: * Viewport rendering stores the result in a `RenderResult`. RenderResult is not aware of the type of data it holds. In many places where RenderResult is used it is assumed that it stores a combined pass and the display+view transform are applied. I will propose to fix this in a future patch. But that is still being designed and discussed. Reviewed By: fclem Differential Revision: https://developer.blender.org/D6319