Bug 1899042 - Remove untested and unimplemented align="char" value for tables. r=jfkthame,layout-reviewers

Other engines also don't implement it, so moderately sure this is safe.

Differential Revision: https://phabricator.services.mozilla.com/D212549

dom/html/nsGenericHTMLElement.cpp

@@ -1222,9 +1222,11 @@ bool nsGenericHTMLElement::ParseAlignValue(const nsAString& aString,
 //----------------------------------------
 
 static const nsAttrValue::EnumTable kTableHAlignTable[] = {
-    {"left", StyleTextAlign::Left},       {"right", StyleTextAlign::Right},
-    {"center", StyleTextAlign::Center},   {"char", StyleTextAlign::Char},
-    {"justify", StyleTextAlign::Justify}, {nullptr, 0}};
+    {"left", StyleTextAlign::Left},
+    {"right", StyleTextAlign::Right},
+    {"center", StyleTextAlign::Center},
+    {"justify", StyleTextAlign::Justify},
+    {nullptr, 0}};
 
 bool nsGenericHTMLElement::ParseTableHAlignValue(const nsAString& aString,
                                                  nsAttrValue& aResult) {
@@ -1238,7 +1240,6 @@ static const nsAttrValue::EnumTable kTableCellHAlignTable[] = {
     {"left", StyleTextAlign::MozLeft},
     {"right", StyleTextAlign::MozRight},
     {"center", StyleTextAlign::MozCenter},
-    {"char", StyleTextAlign::Char},
     {"justify", StyleTextAlign::Justify},
     {"middle", StyleTextAlign::MozCenter},
     {"absmiddle", StyleTextAlign::Center},

layout/generic/nsLineLayout.cpp

@@ -3273,7 +3273,6 @@ void nsLineLayout::TextAlignLine(nsLineBox* aLine, bool aIsLastLine) {
       }
 
       case StyleTextAlign::Start:
-      case StyleTextAlign::Char:
         // Default alignment is to start edge so do nothing, except to apply
         // any "reverse-hang" amount resulting from reversed-direction trailing
         // space.

servo/components/style/values/specified/text.rs

@@ -404,9 +404,6 @@ pub enum TextAlignKeyword {
     Right,
     Center,
     Justify,
-    #[css(skip)]
-    #[cfg(feature = "gecko")]
-    Char,
     End,
     #[parse(aliases = "-webkit-center")]
     MozCenter,