Componentization: make core classes visible for blink_tests and blink_web.

Source/core/dom/PseudoElement.h

Index: Source/core/dom/PseudoElement.h
diff --git a/Source/core/dom/PseudoElement.h b/Source/core/dom/PseudoElement.h
index 8c0d14e7c4f0c2001204c4afccec9289fac096fb..270d8b1378b18eeef5c4199dce831b718067b0f8 100644
--- a/Source/core/dom/PseudoElement.h
+++ b/Source/core/dom/PseudoElement.h
@@ -27,12 +27,13 @@
 #ifndef PseudoElement_h
 #define PseudoElement_h
 
+#include "core/CoreExport.h"
 #include "core/dom/Element.h"
 #include "core/style/ComputedStyle.h"
 
 namespace blink {
 
-class PseudoElement : public Element {
+class CORE_EXPORT PseudoElement : public Element {
 public:
     static PassRefPtrWillBeRawPtr<PseudoElement> create(Element* parent, PseudoId);