Refactoring: Introduce HTMLImport interface to form import tree.

Source/core/html/HTMLImport.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 10 matching lines @@
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * 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();
+
+    virtual HTMLImportsController* controller() = 0;
+    virtual HTMLImport* parent() = 0;
+    virtual Document* document() = 0;
+    virtual void wasDetachedFromDocument() = 0;
 };
 
-void provideMIDITo(Page*, MIDIClient*);
-
 } // namespace WebCore
 
-#endif // MIDIClient_h
+#endif // HTMLImport_h