Maximum number of frames queued up by graphics driver.
Graphics drivers can queue up frames to be rendered. When CPU has much less work to do than the graphics card,
is it possible for this queue to become quite large. In those cases, user's input will "lag behind"
what is on the screen.
Use QualitySettings.maxQueuedFrames to limit maximum number of frames that are queued. The default value is -1,
which does not limit the queue.
Note that using a low maxQueuedFrames value can lower your FPS count, because CPU will be waiting until the graphics card
will finish rendering previous frames. But you will get lower input latency.
Currently maxQueuedFrames is only implemented in Direct3D renderer; it will be ignored in OpenGL.