We build on top of the QPlatformOpenGLContext implementation to get
automatic support for QBackingStore-based painting. Since the OpenGL
renderer does not clear the backingstore between frames, we actually
also get support for partial updates, and we get the benefit of an
accelerated paint engine for Qt Quick 1 without setting a GLWidget
as the viewport, which would cause issues such as an extra QWindow.
This patch also removes the dependency to QtOpenGL and QtWidgets, which
were leftovers from the Qt4 platform plugin. In Qt5 the needed GL bits
are in QtGui.
Change-Id: Id9b736bfb2e4aec56c0fa9f5b7b4d8bff8e3d1dc
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>
09187f602c