mono/MonoGame — pull request #773 by Aranda (2012-09-16 14:24:19+00:00)
Title: Fix dodgy offset resulting from incorrect viewport on Android

Dean noticed that the Draw2D sample was unexpectedly offset. It seems that my recent change to `GraphicsDeviceManager.ResetClientBounds()`, coupled with other recent changes in the `GraphicsDevice.Viewport` setter caused this issue.

Essentially the fix boils down to moving the setting of the Viewport to after the setting of the BackBufferWidth/Height as the GL.Viewport call depends on the buffer size. I've taken the opportunity to comment and slightly clean up the method as it's functionality is not easy to understand at first glance.