Simplify DOMWindowProperty and its unregistration.

As LocalDOMWindow controls the registration lifetime of its
DOMWindowProperties, there's no need to offer a separate unregistration
mechanism. Remove it, simplify notification code + retire now unused
LocalDOMWindow back reference on DOMWindowProperty.

R=haraken,ager
BUG=

Review URL: https://codereview.chromium.org/558213002

git-svn-id: svn://svn.chromium.org/blink/trunk@181758 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/frame/DOMWindowProperty.cpp

@@ -34,39 +34,24 @@ namespace blink {
 
 DOMWindowProperty::DOMWindowProperty(LocalFrame* frame)
     : m_frame(frame)
-    , m_associatedDOMWindow(nullptr)
 {
     // FIXME: For now it *is* acceptable for a DOMWindowProperty to be created with a null frame.
     // See fast/dom/navigator-detached-no-crash.html for the recipe.
     // We should fix that.  <rdar://problem/11567132>
-    if (m_frame) {
-        m_associatedDOMWindow = m_frame->domWindow();
-        m_associatedDOMWindow->registerProperty(this);
-    }
+    if (m_frame)
+        m_frame->domWindow()->registerProperty(this);
 }
 
-#if !ENABLE(OILPAN)
-DOMWindowProperty::~DOMWindowProperty()
-{
-    if (m_associatedDOMWindow)
-        m_associatedDOMWindow->unregisterProperty(this);
-
-    m_associatedDOMWindow = nullptr;
-    m_frame = nullptr;
-}
-#endif
+DEFINE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(DOMWindowProperty);
 
 void DOMWindowProperty::willDestroyGlobalObjectInFrame()
 {
     // If the property is getting this callback it must have been created with a LocalFrame/LocalDOMWindow and it should still have them.
     ASSERT(m_frame);
-    ASSERT(m_associatedDOMWindow);
 
-    // DOMWindowProperty lifetime isn't tied directly to the LocalDOMWindow itself so it is important that it unregister
-    // itself from any LocalDOMWindow it is associated with if that LocalDOMWindow is going away.
-    if (m_associatedDOMWindow)
-        m_associatedDOMWindow->unregisterProperty(this);
-    m_associatedDOMWindow = nullptr;
+    // DOMWindowProperty's registered lifetime is controlled by LocalDOMWindow. After
+    // the willDestroyGlobalObjectInFrame() notifications, LocalDOMWindow clears out
+    // all registrations. Hence no need to unregister.
     m_frame = nullptr;
 }
 
@@ -74,12 +59,6 @@ void DOMWindowProperty::willDetachGlobalObjectFromFrame()
 {
     // If the property is getting this callback it must have been created with a LocalFrame/LocalDOMWindow and it should still have them.
     ASSERT(m_frame);
-    ASSERT(m_associatedDOMWindow);
 }
 
-void DOMWindowProperty::trace(Visitor* visitor)
-{
-    visitor->trace(m_associatedDOMWindow);
-}
-
-}
+} // namespace blink

third_party/WebKit/Source/core/frame/DOMWindowProperty.h

@@ -30,10 +30,10 @@
 
 namespace blink {
 
-class LocalDOMWindow;
 class LocalFrame;
 
 class DOMWindowProperty : public WillBeGarbageCollectedMixin {
+    DECLARE_EMPTY_VIRTUAL_DESTRUCTOR_WILL_BE_REMOVED(DOMWindowProperty);
 public:
     explicit DOMWindowProperty(LocalFrame*);
 
@@ -42,15 +42,10 @@ public:
 
     LocalFrame* frame() const { return m_frame; }
 
-    virtual void trace(Visitor*);
+    virtual void trace(Visitor*) { }
 
 protected:
-#if !ENABLE(OILPAN)
-    virtual ~DOMWindowProperty();
-#endif
-
     LocalFrame* m_frame;
-    RawPtrWillBeMember<LocalDOMWindow> m_associatedDOMWindow;
 };
 
 }

third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp

@@ -556,22 +556,14 @@ void LocalDOMWindow::willDetachFrameHost()
 
 void LocalDOMWindow::willDestroyDocumentInFrame()
 {
-    // It is necessary to copy m_properties to a separate vector because the DOMWindowProperties may
-    // unregister themselves from the LocalDOMWindow as a result of the call to willDestroyGlobalObjectInFrame.
-    WillBeHeapVector<RawPtrWillBeMember<DOMWindowProperty> > properties;
-    copyToVector(m_properties, properties);
-    for (size_t i = 0; i < properties.size(); ++i)
-        properties[i]->willDestroyGlobalObjectInFrame();
+    for (WillBeHeapHashSet<RawPtrWillBeMember<DOMWindowProperty> >::const_iterator it = m_properties.begin(); it != m_properties.end(); ++it)
+        (*it)->willDestroyGlobalObjectInFrame();
 }
 
 void LocalDOMWindow::willDetachDocumentFromFrame()
 {
-    // It is necessary to copy m_properties to a separate vector because the DOMWindowProperties may
-    // unregister themselves from the LocalDOMWindow as a result of the call to willDetachGlobalObjectFromFrame.
-    WillBeHeapVector<RawPtrWillBeMember<DOMWindowProperty> > properties;
-    copyToVector(m_properties, properties);
-    for (size_t i = 0; i < properties.size(); ++i)
-        properties[i]->willDetachGlobalObjectFromFrame();
+    for (WillBeHeapHashSet<RawPtrWillBeMember<DOMWindowProperty> >::const_iterator it = m_properties.begin(); it != m_properties.end(); ++it)
+        (*it)->willDetachGlobalObjectFromFrame();
 }
 
 void LocalDOMWindow::registerProperty(DOMWindowProperty* property)
@@ -579,11 +571,6 @@ void LocalDOMWindow::registerProperty(DOMWindowProperty* property)
     m_properties.add(property);
 }
 
-void LocalDOMWindow::unregisterProperty(DOMWindowProperty* property)
-{
-    m_properties.remove(property);
-}
-
 void LocalDOMWindow::reset()
 {
     willDestroyDocumentInFrame();

third_party/WebKit/Source/core/frame/LocalDOMWindow.h

@@ -112,7 +112,6 @@ public:
     virtual LocalDOMWindow* toDOMWindow() OVERRIDE;
 
     void registerProperty(DOMWindowProperty*);
-    void unregisterProperty(DOMWindowProperty*);
 
     void reset();