Utilize PassRefPtr and C++ refs in more places in ShadowRoot code

Source/core/dom/shadow/ElementShadow.h

 /*
  * Copyright (C) 2012 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.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 17 matching lines @@
 #define ElementShadow_h
 
 #include "core/dom/shadow/InsertionPoint.h"
 #include "core/dom/shadow/SelectRuleFeatureSet.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "wtf/DoublyLinkedList.h"
 #include "wtf/Forward.h"
 #include "wtf/HashMap.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/PassOwnPtr.h"
+#include "wtf/PassRefPtr.h"
 #include "wtf/Vector.h"
 
 namespace WebCore {
 
 class ElementShadow {
     WTF_MAKE_NONCOPYABLE(ElementShadow); WTF_MAKE_FAST_ALLOCATED;
 public:
     static PassOwnPtr<ElementShadow> create();
     ~ElementShadow();
 
     Element* host() const;
     ShadowRoot* youngestShadowRoot() const { return m_shadowRoots.head(); }
     ShadowRoot* oldestShadowRoot() const { return m_shadowRoots.tail(); }
     ElementShadow* containingShadow() const;
 
-    ShadowRoot* addShadowRoot(Element& shadowHost, ShadowRoot::ShadowRootType);
+    PassRefPtr<ShadowRoot> addShadowRoot(Element& shadowHost, ShadowRoot::ShadowRootType);

[eseidel, 2013/11/06 01:11:17]

add methods generally take a PassRefPtr<>, not return one... Should this be
called create?

[adamk, 2013/11/06 02:01:39]

It creates a shadow root and adds it to the shadowHost. I don't think
createShadowRoot is a better name for this method, based on its additive
behavior.

I changed it to return a PassRefPtr since its main caller is
Element::createShadowRoot (which itself returns a PassRefPtr). As noted above,
ShadowRoot is also kept alive by its connection to its host.

 
     bool applyAuthorStyles() const { return m_applyAuthorStyles; }
     bool didAffectApplyAuthorStyles();
     bool containsActiveStyles() const;
 
     void attach(const Node::AttachContext&);
     void detach(const Node::AttachContext&);
 
     void removeAllEventListeners();
 
@@ skipping 59 matching lines @@
 inline void ElementShadow::distributeIfNeeded()
 {
     if (m_needsDistributionRecalc)
         distribute();
     m_needsDistributionRecalc = false;
 }
 
 } // namespace
 
 #endif