Remove the concept of user stylesheets.

Source/core/page/Page.h

Index: Source/core/page/Page.h
diff --git a/Source/core/page/Page.h b/Source/core/page/Page.h
index 9f3e9a639a13648dee022acb20852bfc26943d1a..bda184a01482179d38e3104b91881898143347cd 100644
--- a/Source/core/page/Page.h
+++ b/Source/core/page/Page.h
@@ -182,9 +182,6 @@ public:
     const Pagination& pagination() const { return m_pagination; }
     void setPagination(const Pagination&);
 
-    void userStyleSheetLocationChanged();
-    const String& userStyleSheet() const;
-
     void dnsPrefetchingStateChanged();
 
     static void allVisitedStateChanged(PageGroup*);
@@ -276,9 +273,6 @@ private:
 
     Pagination m_pagination;
 
-    String m_userStyleSheet;
-    bool m_didLoadUserStyleSheet;
-
     RefPtr<PageGroup> m_group;
 
     OwnPtr<StorageNamespace> m_sessionStorage;