Remove the importedDocument functions from HTML imports classes.

Source/core/html/imports/HTMLImportLoader.h

Index: Source/core/html/imports/HTMLImportLoader.h
diff --git a/Source/core/html/imports/HTMLImportLoader.h b/Source/core/html/imports/HTMLImportLoader.h
index e316754d6c9942b6f8fff8ee64857fc9ab084e7e..ac98eb3b8ccd3bcab6ae1ebbe2471e0478d71479 100644
--- a/Source/core/html/imports/HTMLImportLoader.h
+++ b/Source/core/html/imports/HTMLImportLoader.h
@@ -69,8 +69,7 @@ public:
 
     virtual ~HTMLImportLoader();
 
-    Document* document() const { return m_importedDocument.get(); }
-    Document* importedDocument() const;
+    Document* document() const { return m_document.get(); }
     void addImport(HTMLImportChild*);
     void removeImport(HTMLImportChild*);
     void moveToFirst(HTMLImportChild*);
@@ -109,7 +108,7 @@ private:
     HTMLImportsController* m_controller;
     Vector<HTMLImportChild*> m_imports;
     State m_state;
-    RefPtr<Document> m_importedDocument;
+    RefPtr<Document> m_document;
     RefPtr<DocumentWriter> m_writer;
     RefPtr<CustomElementMicrotaskQueue> m_microtaskQueue;
 };