[less] Extract cross-browser normalization rules into new 'normalize.less'

Change-Id: I23da024b47020212173380315acd37210b924327

resources/skins.vector.styles/common/normalize.less

@@ -0,0 +1,12 @@
+/*
+ * Normalize styles across rendering engines.
+ * Ideally, these rules should live in core and be shared across skins.
+ *
+ */
+
+html,
+body {
+	height: 100%;
+	margin: 0;
+	padding: 0;
+}

resources/skins.vector.styles/layout.less

@@ -22,13 +22,6 @@
 	2 * @padding-vertical-header;
 @width-grid-column-one: 11em;
 
-html,
-body {
-	height: 100%;
-	margin: 0;
-	padding: 0;
-}
-
 body {
 	// General background/foreground color definition as one exception to the rule.
 	background-color: @background-color-base;

resources/skins.vector.styles/legacy/layout.less

@@ -4,13 +4,6 @@
 @import 'mediawiki.mixins.less';
 @import '../../../variables.less';
 
-html,
-body {
-	height: 100%;
-	margin: 0;
-	padding: 0;
-}
-
 body {
 	background-color: @background-color-secondary;
 	overflow-y: scroll;

resources/skins.vector.styles/skin-legacy.less

@@ -4,6 +4,7 @@
 @import 'mediawiki.mixins.less';
 
 @media screen {
+	@import 'common/normalize.less';
 	@import 'legacy/layout.less';
 	@import 'common/content.less';
 	@import 'common/typography.less';

resources/skins.vector.styles/skin.less

@@ -4,6 +4,7 @@
 @import 'mediawiki.mixins.less';
 
 @media screen {
+	@import 'common/normalize.less';
 	@import 'layout.less';
 	@import 'common/content.less';
 	@import 'common/typography.less';