[New Multicolumn] Add RenderMultiColumnSpannerSet.

Source/core/rendering/RenderMultiColumnSpannerSet.cpp

Index: Source/core/rendering/RenderMultiColumnSpannerSet.cpp
diff --git a/Source/core/rendering/RenderMultiColumnSpannerSet.cpp b/Source/core/rendering/RenderMultiColumnSpannerSet.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..69ae4f36398f84e73fb69e9fb029b7a511a12baf
--- /dev/null
+++ b/Source/core/rendering/RenderMultiColumnSpannerSet.cpp
@@ -0,0 +1,36 @@
+// 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/rendering/RenderMultiColumnSpannerSet.h"
+
+namespace blink {
+
+RenderMultiColumnSpannerSet* RenderMultiColumnSpannerSet::createAnonymous(RenderMultiColumnFlowThread* flowThread, RenderStyle* parentStyle, RenderBox* rendererInFlowThread)
+{
+    RenderMultiColumnSpannerSet* newSpanner = new RenderMultiColumnSpannerSet(flowThread, rendererInFlowThread);
+    Document& document = flowThread->document();
+    newSpanner->setDocumentForAnonymous(&document);
+    RefPtr<RenderStyle> newStyle = RenderStyle::createAnonymousStyleWithDisplay(parentStyle, BLOCK);
+    newSpanner->setStyle(newStyle);
+    return newSpanner;
+}
+
+RenderMultiColumnSpannerSet::RenderMultiColumnSpannerSet(RenderMultiColumnFlowThread* flowThread, RenderBox* rendererInFlowThread)
+    : RenderMultiColumnSet(flowThread)
+    , m_rendererInFlowThread(rendererInFlowThread)
+{
+}
+
+bool RenderMultiColumnSpannerSet::recalculateColumnHeight(BalancedHeightCalculation calculationMode)
+{
+    return false;
+}
+
+const char* RenderMultiColumnSpannerSet::renderName() const
+{
+    return "RenderMultiColumnSpannerSet";
+}
+
+}