Add support for multiple text decorations with same line positioning

Source/core/layout/LayoutObject.h

Index: Source/core/layout/LayoutObject.h
diff --git a/Source/core/layout/LayoutObject.h b/Source/core/layout/LayoutObject.h
index bf1a812f99b0cb266fc2a9dbb93595dd70ae508e..d962e8945755d3f158748a58f109b95c5c95ba21 100644
--- a/Source/core/layout/LayoutObject.h
+++ b/Source/core/layout/LayoutObject.h
@@ -913,15 +913,6 @@ public:
 
     virtual CursorDirective getCursor(const LayoutPoint&, Cursor&) const;
 
-    struct AppliedTextDecoration {
-        STACK_ALLOCATED();
-        Color color;
-        TextDecorationStyle style;
-        AppliedTextDecoration() : color(Color::transparent), style(TextDecorationStyleSolid) { }
-    };
-
-    void getTextDecorations(unsigned decorations, AppliedTextDecoration& underline, AppliedTextDecoration& overline, AppliedTextDecoration& linethrough, bool quirksMode = false, bool firstlineStyle = false);
-
     // Return the LayoutBoxModelObject in the container chain which is responsible for painting this object, or layout view
     // if painting is root-relative. This is the container that should be passed to the 'forPaintInvalidation'
     // methods.