Detach old frame on WebFrame::swap.

Source/core/frame/Frame.h

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999-2001 Lars Knoll <knoll@kde.org>
  *                     1999-2001 Antti Koivisto <koivisto@kde.org>
  *                     2000-2001 Simon Hausmann <hausmann@kde.org>
  *                     2000-2001 Dirk Mueller <mueller@kde.org>
  *                     2000 Stefan Schimanski <1Stein@gmx.de>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
@@ skipping 37 matching lines @@
 class HTMLFrameOwnerElement;
 class LayoutPart;
 class KURL;
 class Page;
 class SecurityContext;
 class Settings;
 class WindowProxy;
 class WindowProxyManager;
 struct FrameLoadRequest;
 
+enum class FrameDetachType { Remove, Swap };
+
 // Status of user gesture.
 enum class UserGestureStatus { Active, None };
 
 class CORE_EXPORT Frame : public RefCountedWillBeGarbageCollectedFinalized<Frame> {
 public:
     virtual ~Frame();
 
     DECLARE_VIRTUAL_TRACE();
 
     virtual bool isLocalFrame() const { return false; }
     virtual bool isRemoteFrame() const { return false; }
 
     virtual DOMWindow* domWindow() const = 0;
     virtual WindowProxy* windowProxy(DOMWrapperWorld&) = 0;
 
     virtual void navigate(Document& originDocument, const KURL&, bool lockBackForwardList, UserGestureStatus) = 0;
     // This version of Frame::navigate assumes the resulting navigation is not
     // to be started on a timer. Use the method above in such cases.
     virtual void navigate(const FrameLoadRequest&) = 0;
     virtual void reload(FrameLoadType, ClientRedirectPolicy) = 0;
 
-    virtual void detach();
+    virtual void detach(FrameDetachType);
     void detachChildren();
     virtual void disconnectOwnerElement();
 
     FrameClient* client() const;
 
     // NOTE: Page is moving out of Blink up into the browser process as
     // part of the site-isolation (out of process iframes) work.
     // FrameHost should be used instead where possible.
     Page* page() const;
     FrameHost* host() const; // Null when the frame is detached.
 
     bool isMainFrame() const;
     bool isLocalRoot() const;
 
     FrameOwner* owner() const;
     void setOwner(FrameOwner* owner) { m_owner = owner; }
     HTMLFrameOwnerElement* deprecatedLocalOwner() const;
 
     FrameTree& tree() const;
     ChromeClient& chromeClient() const;
 
     virtual SecurityContext* securityContext() const = 0;
 
     Frame* findFrameForNavigation(const AtomicString& name, Frame& activeFrame);
     Frame* findUnsafeParentScrollPropagationBoundary();
 
+    // This prepares the Frame for the next commit. It will detach children,
+    // dispatch unload events, abort XHR requests and detach the document.
+    // Returns true if the frame is ready to receive the next commit, or false
+    // otherwise.
+    virtual bool prepareForCommit() = 0;
+    void prepareSwapFrom(Frame*);
     void finishSwapFrom(Frame*);
 
     bool canNavigate(const Frame&);
     virtual void printNavigationErrorMessage(const Frame&, const char* reason) = 0;
 
     LayoutPart* ownerLayoutObject() const; // LayoutObject for the element that contains this frame.
 
     int64_t frameID() const { return m_frameID; }
 
     Settings* settings() const; // can be null
@@ skipping 36 matching lines @@
 {
     return m_treeNode;
 }
 
 // Allow equality comparisons of Frames by reference or pointer, interchangeably.
 DEFINE_COMPARISON_OPERATORS_WITH_REFERENCES_REFCOUNTED(Frame)
 
 } // namespace blink
 
 #endif // Frame_h