Refactoring: Introduce HTMLImport interface to form import tree.

Source/core/html/HTMLImport.h

Index: Source/core/html/HTMLImport.h
diff --git a/Source/modules/webmidi/MIDIClient.h b/Source/core/html/HTMLImport.h
similarity index 81%
copy from Source/modules/webmidi/MIDIClient.h
copy to Source/core/html/HTMLImport.h
index 5c797c4fb22a1b126728355b4f091546ec007d5f..afcec1728d0471c54f5b1418f10a27561a2d1004 100644
--- a/Source/modules/webmidi/MIDIClient.h
+++ b/Source/core/html/HTMLImport.h
@@ -28,27 +28,26 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef MIDIClient_h
-#define MIDIClient_h
-
-#include "wtf/PassRefPtr.h"
+#ifndef HTMLImport_h
+#define HTMLImport_h
 
 namespace WebCore {
 
-class MIDIAccess;
-class Page;
+class Document;
+class HTMLImportsController;
 
-class MIDIClient {
+class HTMLImport {
 public:
-    virtual void requestSysExPermission(PassRefPtr<MIDIAccess>) = 0;
-    virtual void cancelSysExPermissionRequest(MIDIAccess*) = 0;
+    virtual ~HTMLImport() { }
 
-protected:
-    virtual ~MIDIClient() { }
-};
+    bool haveChildrenLoaded();
 
-void provideMIDITo(Page*, MIDIClient*);
+    virtual HTMLImportsController* controller() = 0;
+    virtual HTMLImport* parent() = 0;
+    virtual Document* document() = 0;
+    virtual void wasDetachedFromDocument() = 0;
+};
 
 } // namespace WebCore
 
-#endif // MIDIClient_h
+#endif // HTMLImport_h