Componentization: make core/dom visible for blink_web and blink_tests.

Source/core/dom/DocumentLifecycleObserver.h

Index: Source/core/dom/DocumentLifecycleObserver.h
diff --git a/Source/core/dom/DocumentLifecycleObserver.h b/Source/core/dom/DocumentLifecycleObserver.h
index c5e5fefb70d77c1e1e28ccb5c1405b54b3c8c6d0..f71a9030b2ebee1e84865a99423c938420d47fd9 100644
--- a/Source/core/dom/DocumentLifecycleObserver.h
+++ b/Source/core/dom/DocumentLifecycleObserver.h
@@ -26,6 +26,7 @@
 #ifndef DocumentLifecycleObserver_h
 #define DocumentLifecycleObserver_h
 
+#include "core/CoreExport.h"
 #include "core/dom/Document.h"
 #include "platform/LifecycleObserver.h"
 
@@ -33,7 +34,7 @@ namespace blink {
 
 class DocumentLifecycleNotifier;
 
-class DocumentLifecycleObserver : public LifecycleObserver<Document, DocumentLifecycleObserver, DocumentLifecycleNotifier> {
+class CORE_EXPORT DocumentLifecycleObserver : public LifecycleObserver<Document, DocumentLifecycleObserver, DocumentLifecycleNotifier> {
 public:
     virtual void documentWasDetached() { }
 #if !ENABLE(OILPAN)