Change Rect and Quad to be CSSValues

Source/core/css/CSSQuadValue.cpp

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "core/css/CSSQuadValue.h"
+
+#include "wtf/text/StringBuilder.h"
+
+namespace blink {
+
+String CSSQuadValue::generateCSSString(const String& top, const String& right, const String& bottom, const String& left, bool serializeAsRect)
+{
+    if (serializeAsRect)
+        return "rect(" + top + ' ' + right + ' ' + bottom + ' ' + left + ')';
+
+    StringBuilder result;
+    // reserve space for the four strings, plus three space separator characters.
+    result.reserveCapacity(top.length() + right.length() + bottom.length() + left.length() + 3);
+    result.append(top);
+    if (right != top || bottom != top || left != top) {
+        result.append(' ');
+        result.append(right);
+        if (bottom != top || right != left) {
+            result.append(' ');
+            result.append(bottom);
+            if (left != right) {
+                result.append(' ');
+                result.append(left);
+            }
+        }
+    }
+    return result.toString();
+}
+
+DEFINE_TRACE_AFTER_DISPATCH(CSSQuadValue)
+{
+    visitor->trace(m_top);
+    visitor->trace(m_right);
+    visitor->trace(m_bottom);
+    visitor->trace(m_left);
+    CSSValue::traceAfterDispatch(visitor);
+}
+
+}