Remove mediawiki stylesheet hack

Source/core/css/StyleSheetContents.cpp

Index: Source/core/css/StyleSheetContents.cpp
diff --git a/Source/core/css/StyleSheetContents.cpp b/Source/core/css/StyleSheetContents.cpp
index 1bcbbdafce75e21acb349c32c3845f61ba7782ff..5e670ee52ab47d5f491bb5680f04f1cfe957039b 100644
--- a/Source/core/css/StyleSheetContents.cpp
+++ b/Source/core/css/StyleSheetContents.cpp
@@ -293,15 +293,6 @@ void StyleSheetContents::parseAuthorStyleSheet(const CSSStyleSheetResource* cach
             return;
         }
     }
-    if (!quirksMode && m_parserContext.needsSiteSpecificQuirks) {
-        // Work around <https://bugs.webkit.org/show_bug.cgi?id=28350>.
-        DEFINE_STATIC_LOCAL(const String, mediaWikiKHTMLFixesStyleSheet, ("/* KHTML fix stylesheet */\n/* work around the horizontal scrollbars */\n#column-content { margin-left: 0; }\n\n"));
-        // There are two variants of KHTMLFixes.css. One is equal to mediaWikiKHTMLFixesStyleSheet,
-        // while the other lacks the second trailing newline.
-        if (baseURL().string().endsWith("/KHTMLFixes.css") && !sheetText.isNull() && mediaWikiKHTMLFixesStyleSheet.startsWith(sheetText)
-            && sheetText.length() >= mediaWikiKHTMLFixesStyleSheet.length() - 1)
-            clearRules();
-    }
 }
 
 bool StyleSheetContents::parseString(const String& sheetText)