[Visualizer] Add extra condition to visible check

Add an extra condition to the visibility check, which is similar to the
previous version of this check, which now guards against the window it
is hosted in not being visible.

Signed-off-by: Christopher Snowhill <kode54@gmail.com>

Utils/NSView+Visibility.m

@@ -14,6 +14,10 @@
 		return NO;
 	}
 
+	if(![self.window isVisible]) {
+		return NO;
+	}
+
 	// Might have zero opacity.
 	if(self.alphaValue == 0 || self.hiddenOrHasHiddenAncestor) {
 		return NO;