Move Location to DOMWindow

Source/core/frame/Location.h

 /*
  * Copyright (C) 2008, 2010 Apple 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 22 matching lines @@
 #include "core/dom/DOMStringList.h"
 #include "core/frame/DOMWindowProperty.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefCounted.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class LocalDOMWindow;
 class ExceptionState;
-class LocalFrame;
+class Frame;
 class KURL;
 
-class Location final : public RefCountedWillBeGarbageCollected<Location>, public ScriptWrappable, public DOMWindowProperty {
+// This class corresponds to the JS Location API, which is the only DOM API besides Window that is operable
+// in a RemoteFrame. Rather than making DOMWindowProperty support RemoteFrames and generating a lot
+// code churn, Location is implemented as a one-off with some custom lifetime management code. Namely,
+// it needs a manual call to reset() from DOMWindow::reset() to ensure it doesn't retain a stale Frame pointer.
+class Location final : public RefCountedWillBeGarbageCollected<Location>, public ScriptWrappable {
     DEFINE_WRAPPERTYPEINFO();
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(Location);

[sof, 2015/02/07 17:09:32]

With Location no longer deriving from DOMWindowProperty, it is no longer a
mixin, so this needs to be removed also.

[Nate Chapin, 2015/02/10 19:45:27]

Done.

 public:
-    static PassRefPtrWillBeRawPtr<Location> create(LocalFrame* frame)
+    static PassRefPtrWillBeRawPtr<Location> create(Frame* frame)
     {
         return adoptRefWillBeNoop(new Location(frame));
     }
 
+    Frame* frame() const { return m_frame.get(); }
+    void reset() { m_frame = nullptr; }
+
     void setHref(LocalDOMWindow* callingWindow, LocalDOMWindow* enteredWindow, const String&);
     String href() const;
 
     void assign(LocalDOMWindow* callingWindow, LocalDOMWindow* enteredWindow, const String&);
     void replace(LocalDOMWindow* callingWindow, LocalDOMWindow* enteredWindow, const String&);
     void reload(LocalDOMWindow* callingWindow);
 
     void setProtocol(LocalDOMWindow* callingWindow, LocalDOMWindow* enteredWindow, const String&, ExceptionState&);
     String protocol() const;
     void setHost(LocalDOMWindow* callingWindow, LocalDOMWindow* enteredWindow, const String&);
     String host() const;
     void setHostname(LocalDOMWindow* callingWindow, LocalDOMWindow* enteredWindow, const String&);
     String hostname() const;
     void setPort(LocalDOMWindow* callingWindow, LocalDOMWindow* enteredWindow, const String&);
     String port() const;
     void setPathname(LocalDOMWindow* callingWindow, LocalDOMWindow* enteredWindow, const String&);
     String pathname() const;
     void setSearch(LocalDOMWindow* callingWindow, LocalDOMWindow* enteredWindow, const String&);
     String search() const;
     void setHash(LocalDOMWindow* callingWindow, LocalDOMWindow* enteredWindow, const String&);
     String hash() const;
     String origin() const;
 
     PassRefPtrWillBeRawPtr<DOMStringList> ancestorOrigins() const;
 
-    virtual void trace(Visitor*) override;
+    virtual void trace(Visitor*);
 
 private:
-    explicit Location(LocalFrame*);
+    explicit Location(Frame*);
 
     enum class SetLocation { Normal, ReplaceThisFrame };
     void setLocation(const String&, LocalDOMWindow* callingWindow, LocalDOMWindow* enteredWindow, SetLocation = SetLocation::Normal);
 
     const KURL& url() const;
+
+    RawPtrWillBeWeakMember<Frame> m_frame;

[sof, 2015/02/07 17:09:32]

Don't need a weak reference here as the reference is cleared on detach in any
case; switch to RawPtrWillBeMember<> ?

[haraken, 2015/02/08 01:19:40]

I'm curious about this. It seems that Location should not keep Frame alive, so
this needs to be a WeakMember even though it is explicitly cleared?

[sof, 2015/02/08 06:42:13]

It could only keep it separately alive if the reference to Location from the
DOMWindow is independently lost, right?

When is the DOMWindow=>Location reference lost? When it is reset, which happens
at the same time that this (Location=>DOMWindow) reference is cleared.

 };
 
 } // namespace blink
 
 #endif // Location_h