[LayoutNG] Initial support for multicol, introducing NGBlockBreakToken.

third_party/WebKit/Source/core/style/StyleMultiColData.h

Index: third_party/WebKit/Source/core/style/StyleMultiColData.h
diff --git a/third_party/WebKit/Source/core/style/StyleMultiColData.h b/third_party/WebKit/Source/core/style/StyleMultiColData.h
index 0b4108e2c4cb3227243c9e45e248e10913f9507d..90c2133eb6155202868b4bf6119b828a033af497 100644
--- a/third_party/WebKit/Source/core/style/StyleMultiColData.h
+++ b/third_party/WebKit/Source/core/style/StyleMultiColData.h
@@ -25,6 +25,7 @@
 #ifndef StyleMultiColData_h
 #define StyleMultiColData_h
 
+#include "core/CoreExport.h"
 #include "core/style/BorderValue.h"
 #include "core/style/ComputedStyleConstants.h"
 #include "wtf/PassRefPtr.h"
@@ -34,7 +35,7 @@ namespace blink {
 
 // CSS3 Multi Column Layout
 
-class StyleMultiColData : public RefCounted<StyleMultiColData> {
+class CORE_EXPORT StyleMultiColData : public RefCounted<StyleMultiColData> {
  public:
   static PassRefPtr<StyleMultiColData> create() {
     return adoptRef(new StyleMultiColData);