Invert the owning relationship between WebFrame and Frame.

Source/web/WebFrameImpl.h

 /*
  * Copyright (C) 2009 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 17 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef WebFrameImpl_h
 #define WebFrameImpl_h
 
 #include "WebFrame.h"
 
 #include "FrameLoaderClientImpl.h"
 #include "core/frame/Frame.h"
-#include "core/frame/FrameDestructionObserver.h"
 #include "platform/geometry/FloatRect.h"
 #include "public/platform/WebFileSystemType.h"
 #include "wtf/Compiler.h"
 #include "wtf/OwnPtr.h"
 #include "wtf/RefCounted.h"
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 class GraphicsContext;
 class HTMLInputElement;
@@ skipping 17 matching lines @@
 class WebPluginContainerImpl;
 class WebView;
 class WebViewImpl;
 struct WebPrintParams;
 
 template <typename T> class WebVector;
 
 // Implementation of WebFrame, note that this is a reference counted object.
 class WebFrameImpl
     : public WebFrame
-    , public RefCounted<WebFrameImpl>
-    , public WebCore::FrameDestructionObserver {
+    , public RefCounted<WebFrameImpl> {
 public:
     // WebFrame methods:
     virtual void close();
     virtual WebString uniqueName() const;
     virtual WebString assignedName() const;
     virtual void setName(const WebString&);
     virtual long long embedderIdentifier() const;
     virtual WebVector<WebIconURL> iconURLs(int iconTypesMask) const;
     virtual void setRemoteWebLayer(WebLayer*);
     virtual void setPermissionClient(WebPermissionClient*);
@@ skipping 142 matching lines @@
 
     virtual WebString contentAsText(size_t maxChars) const;
     virtual WebString contentAsMarkup() const;
     virtual WebString renderTreeAsText(RenderAsTextControls toShow = RenderAsTextNormal) const;
     virtual WebString markerTextForListItem(const WebElement&) const;
     virtual WebRect selectionBoundsRect() const;
 
     virtual bool selectionStartHasSpellingMarkerFor(int from, int length) const;
     virtual WebString layerTreeAsText(bool showDebugInfo = false) const;
 
-    // WebCore::FrameDestructionObserver methods.
-    virtual void willDetachFrameHost();
+    void willDetachParent();
 
     static WebFrameImpl* create(WebFrameClient*);
     // FIXME: Move the embedderIdentifier concept fully to the embedder and
     // remove this factory method.
     static WebFrameImpl* create(WebFrameClient*, long long embedderIdentifier);
     virtual ~WebFrameImpl();
 
     // Called by the WebViewImpl to initialize the main frame for the page.
     void initializeAsMainFrame(WebCore::Page*);
 
@@ skipping 42 matching lines @@
     // allows us to navigate by pressing Enter after closing the Find box.
     void setFindEndstateFocusAndSelection();
 
     void didFail(const WebCore::ResourceError&, bool wasProvisional);
 
     // Sets whether the WebFrameImpl allows its document to be scrolled.
     // If the parameter is true, allow the document to be scrolled.
     // Otherwise, disallow scrolling.
     void setCanHaveScrollbars(bool);
 
+    WebCore::Frame* frame() const { return m_frame.get(); }
     WebFrameClient* client() const { return m_client; }
     void setClient(WebFrameClient* client) { m_client = client; }
 
     WebPermissionClient* permissionClient() { return m_permissionClient; }
     SharedWorkerRepositoryClientImpl* sharedWorkerRepositoryClient() const { return m_sharedWorkerRepositoryClient.get(); }
 
     void setInputEventsTransformForEmulation(const WebCore::IntSize&, float);
 
     static void selectWordAroundPosition(WebCore::Frame*, WebCore::VisiblePosition);
 
@@ skipping 19 matching lines @@
     enum AreaToInvalidate {
       InvalidateNothing,
       InvalidateContentArea,
       InvalidateScrollbar,   // Vertical scrollbar only.
       InvalidateAll          // Both content area and the scrollbar.
     };
 
     WebFrameImpl(WebFrameClient*, long long frame_identifier);
 
     // Sets the local WebCore frame and registers destruction observers.
-    void setWebCoreFrame(WebCore::Frame*);
+    void setWebCoreFrame(PassRefPtr<WebCore::Frame>);
 
     // Notifies the delegate about a new selection rect.
     void reportFindInPageSelection(
         const WebRect& selectionRect, int activeMatchOrdinal, int identifier);
 
     // Clear the find-in-page matches cache forcing rects to be fully
     // calculated again next time updateFindMatchRects is called.
     void clearFindMatchesCache();
 
     // Check if the activeMatchFrame still exists in the frame tree.
@@ skipping 77 matching lines @@
             : WebCore::FrameInit(frameID)
             , m_frameLoaderClientImpl(webFrameImpl)
         {
             setFrameLoaderClient(&m_frameLoaderClientImpl);
         }
 
         FrameLoaderClientImpl m_frameLoaderClientImpl;
     };
     RefPtr<WebFrameInit> m_frameInit;
 
+    // The cycle of madness.

[eseidel, 2013/12/21 01:17:34]

Something a bit more informative. :)

[dcheng, 2013/12/28 01:04:29]

Oops. This was a leftover comment from my initial patch =)
I've updated it to document when it's expected to be set and when it's expected
to be null. The .cpp implementation covers the interaction with the embedder in
more detail.

+    RefPtr<WebCore::Frame> m_frame;
+
     WebFrameClient* m_client;
     WebPermissionClient* m_permissionClient;
     OwnPtr<SharedWorkerRepositoryClientImpl> m_sharedWorkerRepositoryClient;
 
     // A way for the main frame to keep track of which frame has an active
     // match. Should be 0 for all other frames.
     WebFrameImpl* m_currentActiveMatchFrame;
 
     // The range of the active match for the current frame.
     RefPtr<WebCore::Range> m_activeMatch;
@@ skipping 71 matching lines @@
     // Stores the additional input events offset and scale when device metrics emulation is enabled.
     WebCore::IntSize m_inputEventsOffsetForEmulation;
     float m_inputEventsScaleFactorForEmulation;
 };
 
 DEFINE_TYPE_CASTS(WebFrameImpl, WebFrame, frame, true, true);
 
 } // namespace blink
 
 #endif