HTMLImportsController does not need to hold Document ptr.

Source/core/html/imports/HTMLImportsController.cpp

 /*
  * 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 32 matching lines @@
 
 void HTMLImportsController::provideTo(Document& master)
 {
     DEFINE_STATIC_LOCAL(const char*, name, ("HTMLImportsController"));
     OwnPtrWillBeRawPtr<HTMLImportsController> controller = adoptPtrWillBeNoop(new HTMLImportsController(master));
     master.setImportsController(controller.get());
     DocumentSupplement::provideTo(master, name, controller.release());
 }
 
 HTMLImportsController::HTMLImportsController(Document& master)
-    : m_master(&master)
-    , m_root(HTMLImportTreeRoot::create(&master))
+    : m_root(HTMLImportTreeRoot::create(&master))
 {
 }
 
 HTMLImportsController::~HTMLImportsController()
 {
-    ASSERT(!m_master);
+    ASSERT(!m_root);
 }
 
 void HTMLImportsController::clear()
 {
+    Document* master = root()->document();
     m_root.clear();
 
     for (size_t i = 0; i < m_loaders.size(); ++i)
         m_loaders[i]->importDestroyed();
     m_loaders.clear();
 
-    if (m_master)
-        m_master->setImportsController(0);
-    m_master = 0;
-
-    m_root.clear();
+    if (master)
+        master->setImportsController(0);
+    master = 0;
 }
 
 static bool makesCycle(HTMLImport* parent, const KURL& url)
 {
     for (HTMLImport* ancestor = parent; ancestor; ancestor = ancestor->parent()) {
         if (!ancestor->isRoot() && equalIgnoringFragmentIdentifier(toHTMLImportChild(parent)->url(), url))
             return true;
     }
 
     return false;
@@ skipping 15 matching lines @@
     ASSERT(parent == root() || toHTMLImportChild(parent)->loader()->isFirstImport(toHTMLImportChild(parent)));
 
     if (HTMLImportChild* childToShareWith = root()->find(request.url())) {
         HTMLImportLoader* loader = childToShareWith->loader();
         ASSERT(loader);
         HTMLImportChild* child = createChild(request.url(), loader, parent, client);
         child->didShareLoader();
         return child;
     }
 
-    bool sameOriginRequest = securityOrigin()->canRequest(request.url());
+    bool sameOriginRequest = master()->securityOrigin()->canRequest(request.url());
     request.setCrossOriginAccessControl(
-        securityOrigin(), sameOriginRequest ? AllowStoredCredentials : DoNotAllowStoredCredentials,
+        master()->securityOrigin(), sameOriginRequest ? AllowStoredCredentials : DoNotAllowStoredCredentials,
         ClientDidNotRequestCredentials);
     ResourcePtr<RawResource> resource = parent->document()->fetcher()->fetchImport(request);
     if (!resource)
         return 0;
 
     HTMLImportLoader* loader = createLoader();
     HTMLImportChild* child = createChild(request.url(), loader, parent, client);
     // We set resource after the import tree is built since
     // Resource::addClient() immediately calls back to feed the bytes when the resource is cached.
     loader->startLoading(resource);
     child->didStartLoading();
 
     return child;
 }
 
 void HTMLImportsController::showSecurityErrorMessage(const String& message)
 {
-    m_master->addConsoleMessage(JSMessageSource, ErrorMessageLevel, message);
+    master()->addConsoleMessage(JSMessageSource, ErrorMessageLevel, message);
 }
 
-SecurityOrigin* HTMLImportsController::securityOrigin() const
+Document* HTMLImportsController::master() const
 {
-    return m_master->securityOrigin();
-}
-
-ResourceFetcher* HTMLImportsController::fetcher() const
-{
-    return m_master->fetcher();
-}
-
-LocalFrame* HTMLImportsController::frame() const
-{
-    return m_master->frame();
+    return root()->document();
 }
 
 bool HTMLImportsController::shouldBlockScriptExecution(const Document& document) const
 {
     ASSERT(document.importsController() == this);
     if (HTMLImportLoader* loader = loaderFor(document))
         return loader->shouldBlockScriptExecution();
     return root()->state().shouldBlockScriptExecution();
 }
 
 void HTMLImportsController::wasDetachedFrom(const Document& document)
 {
     ASSERT(document.importsController() == this);
-    if (m_master == &document)
+    if (master() == &document)
         clear();
 }
 
 HTMLImportLoader* HTMLImportsController::createLoader()
 {
     m_loaders.append(HTMLImportLoader::create(this));
     return m_loaders.last().get();
 }
 
 HTMLImportLoader* HTMLImportsController::loaderFor(const Document& document) const
 {
     for (size_t i = 0; i < m_loaders.size(); ++i) {
         if (m_loaders[i]->document() == &document)
             return m_loaders[i].get();
     }
 
     return 0;
 }
 
 } // namespace WebCore