Turns out, we don't try to initialize a graphics context, much less
*acquire* one. e.g. Window instances can have many frames (subwindows),
of which one some are really being used at any time so we try to
"steal" one of the graphics contexts from the frame to use ourself,
later on that frame will steal it from someone else, etc.

Change-Id: I66d5dbb7015301bc2d2be51627061c91e1f2ee5d