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

Source/core/dom/DocumentInit.h

Index: Source/core/dom/DocumentInit.h
diff --git a/Source/core/dom/DocumentInit.h b/Source/core/dom/DocumentInit.h
index bf82738d48af4ace76d4cedbaf9e8237814da919..4b3437bfd73a258ff7e61da35dc0370be4b7e702 100644
--- a/Source/core/dom/DocumentInit.h
+++ b/Source/core/dom/DocumentInit.h
@@ -28,8 +28,10 @@
 #ifndef DocumentInit_h
 #define DocumentInit_h
 
+#include "core/CoreExport.h"
 #include "core/dom/SandboxFlags.h"
 #include "core/dom/SecurityContext.h"
+#include "core/dom/custom/CustomElementRegistrationContext.h"
 #include "platform/heap/Handle.h"
 #include "platform/weborigin/KURL.h"
 #include "wtf/PassRefPtr.h"
@@ -38,13 +40,12 @@
 
 namespace blink {
 
-class CustomElementRegistrationContext;
 class Document;
 class LocalFrame;
 class HTMLImportsController;
 class Settings;
 
-class DocumentInit final {
+class CORE_EXPORT DocumentInit final {
     STACK_ALLOCATED();
 public:
     explicit DocumentInit(const KURL& = KURL(), LocalFrame* = 0, WeakPtrWillBeRawPtr<Document> = nullptr, HTMLImportsController* = 0);