CSS: Use pre-defined displays for html and body

Ref 60f546ac
Ref 274feb53cc9a99633dfac785d8b3b837d192c43c
Ref a7724186c98734529b06bebb8f2dc7fc2b641011

src/css/defaultDisplay.js

@@ -4,7 +4,13 @@ define([
 ], function( jQuery ) {
 
 var iframe,
-	elemdisplay = {};
+	elemdisplay = {
+
+		// Support: Firefox
+		// We have to pre-define this values for FF (#10227)
+		HTML: "block",
+		BODY: "block"
+	};
 
 /**
  * Retrieve the actual display of a element