Refactoring: Get rid of HTMLImportRoot.

Source/core/html/imports/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 23 matching lines @@
 #include "core/html/imports/HTMLImportState.h"
 #include "wtf/TreeNode.h"
 #include "wtf/Vector.h"
 
 namespace WebCore {
 
 class CustomElementMicrotaskImportStep;
 class Document;
 class LocalFrame;
 class HTMLImportChild;
-class HTMLImportRoot;
 class HTMLImportsController;
 class KURL;
 
 //
 // # Basic Data Structure and Algorithms of HTML Imports implemenation.
 //
 // ## The Import Tree
 //
 // HTML Imports form a tree:
 //
 // * The root of the tree is HTMLImportsController, which is owned by the master
-//   document as a DocumentSupplement. HTMLImportsController has an abstract class called
-//   HTMLImportRoot to deal with cycler dependency.
+//   document as a DocumentSupplement.
 //
 // * The non-root nodes are HTMLImportChild, which is owned by LinkStyle, that is owned by HTMLLinkElement.
 //   LinkStyle is wired into HTMLImportChild by implementing HTMLImportChildClient interface
 //
 // * Both HTMLImportsController and HTMLImportChild are derived from HTMLImport superclass
 //   that models the tree data structure using WTF::TreeNode and provides a set of
 //   virtual functions.
 //
 // HTMLImportsController also owns all loaders in the tree and manages their lifetime through it.
 // One assumption is that the tree is append-only and nodes are never inserted in the middle of the tree nor removed.
 //
 //
-//    HTMLImport <|- HTMLImportRoot <|- HTMLImportsController <- Document
-//                                      *
-//                                      |
-//               <|-                    HTMLImportChild <- LinkStyle <- HTMLLinkElement
+//    HTMLImport <|- HTMLImportsController <- Document
+//                   *
+//                   |
+//               <|- HTMLImportChild <- LinkStyle <- HTMLLinkElement
 //
 //
 // # Import Sharing and HTMLImportLoader
 //
 // The HTML Imports spec calls for de-dup mechanism to share already loaded imports.
 // To implement this, the actual loading machinery is split out from HTMLImportChild to
 // HTMLImportLoader, and each loader shares HTMLImportLoader with other loader if the URL is same.
 // Check around HTMLImportsController::findLink() for more detail.
 //
 // HTMLImportLoader can be shared by multiple imports.
@@ skipping 16 matching lines @@
 // This represents the import tree data structure.
 class HTMLImport : public TreeNode<HTMLImport> {
 public:
     enum SyncMode {
         Sync  = 0,
         Async = 1
     };
 
     virtual ~HTMLImport() { }
 
+    HTMLImport* root();
     bool isRoot() const { return !isChild(); }
     bool isSync() const { return SyncMode(m_sync) == Sync; }
     const HTMLImportState& state() const { return m_state; }
 
     void appendChild(HTMLImport*);
 
     virtual bool isChild() const { return false; }
-    virtual HTMLImportRoot* root() = 0;
     virtual Document* document() const = 0;
     virtual bool isDone() const = 0; // FIXME: Should be renamed to haveFinishedLoading()
     virtual bool hasLoader() const = 0;
     virtual bool ownsLoader() const { return false; }
     virtual CustomElementMicrotaskImportStep* customElementMicrotaskStep() const { return 0; }
+    virtual void stateWillChange() { }
     virtual void stateDidChange();
 
 protected:
     // Stating from most conservative state.
     // It will be corrected through state update flow.
     explicit HTMLImport(SyncMode sync)
         : m_sync(sync)
     { }
 
-    void stateWillChange();
     static void recalcTreeState(HTMLImport* root);
 
 #if !defined(NDEBUG)
     void show();
     void showTree(HTMLImport* highlight, unsigned depth);
     virtual void showThis();
 #endif
 
 private:
     HTMLImportState m_state;
     unsigned m_sync : 1;
 };
 
-// An abstract class to decouple its sublcass HTMLImportsController.
-class HTMLImportRoot : public HTMLImport {
-public:
-    HTMLImportRoot() : HTMLImport(Sync) { }
-
-    virtual void scheduleRecalcState() = 0;
-    virtual HTMLImportsController* toController() = 0;
-    virtual HTMLImportChild* findLinkFor(const KURL&, HTMLImport* excluding = 0) const = 0;
-};
-
 } // namespace WebCore
 
 #endif // HTMLImport_h