servo: Merge #16609 - Implement unitless length quirk (from nox:quirks); r=Manishearth,emilio

The Gecko side doesn't propagate its quirks mode yet.

Source-Repo: https://github.com/servo/servo
Source-Revision: d8bcc0db1aad26e007b7e2bdeda3cea4953c0db0

servo/components/script/dom/document.rs

@@ -542,7 +542,7 @@ impl Document {
         self.quirks_mode.set(mode);
 
         if mode == QuirksMode::Quirks {
-            self.window.layout_chan().send(Msg::SetQuirksMode).unwrap();
+            self.window.layout_chan().send(Msg::SetQuirksMode(mode)).unwrap();
         }
     }