Remove unused MarginBoxType

Review URL: https://codereview.chromium.org/1323943008

git-svn-id: svn://svn.chromium.org/blink/trunk@201640 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/css/CSSSelector.h

@@ -203,25 +203,6 @@ public:
         PseudoListBox
     };
 
-    enum MarginBoxType {
-        TopLeftCornerMarginBox,
-        TopLeftMarginBox,
-        TopCenterMarginBox,
-        TopRightMarginBox,
-        TopRightCornerMarginBox,
-        BottomLeftCornerMarginBox,
-        BottomLeftMarginBox,
-        BottomCenterMarginBox,
-        BottomRightMarginBox,
-        BottomRightCornerMarginBox,
-        LeftTopMarginBox,
-        LeftMiddleMarginBox,
-        LeftBottomMarginBox,
-        RightTopMarginBox,
-        RightMiddleMarginBox,
-        RightBottomMarginBox,
-    };
-
     enum AttributeMatchType {
         CaseSensitive,
         CaseInsensitive,