Summary:
This is the initial implementation of a DRM backend based on the EGLDevice,
EGLOutput, and EGLStream extensions, supporting NVIDIA graphics hardware using
their proprietary driver. The new backend will be used if the environment
variable KWIN_DRM_USE_EGL_STREAMS is set. On initialization, it will attempt to
create an EGLDevice based on the DRM device currently in use and create
EGLOutputs and EGLStreams for any attached displays. These are used to control
presentation of the final composited frame. Additionally, it will register the
wl_eglstream_controller Wayland interface so that native EGL windows created by
clients can be attached to an EGLStream allowing buffer contents to be shared
with the compositor as a GL texture.

At this time there are two known bugs in the NVIDIA driver's EGL implementation
affecting desktop functionality. The first can result in tooltip windows drawn
by plasmashell to contain incorrect contents. The second...