Merge "Upon double registration just return instead of throwing exception" into tm-qpr-dev

        if (mWindowLayoutChangeListeners.containsKey(context)

                // In theory this method can be called on the same consumer with different context.

                || mWindowLayoutChangeListeners.containsValue(consumer)) {

            throw new IllegalArgumentException(

                    "Context or Consumer has already been registered for WindowLayoutInfo"

                            + " callback.");

            return;

        }

        if (!context.isUiContext()) {

            throw new IllegalArgumentException("Context must be a UI Context, which should be"