Prepare for remote->local frame swap

Source/web/WebFrame.cpp

Index: Source/web/WebFrame.cpp
diff --git a/Source/web/WebFrame.cpp b/Source/web/WebFrame.cpp
index c11f2e11122518e8ec0030f07e42c33a4bc5db89..112978a8d26b922d067355bf4d12e215e7dd8b54 100644
--- a/Source/web/WebFrame.cpp
+++ b/Source/web/WebFrame.cpp
@@ -41,10 +41,6 @@ bool WebFrame::swap(WebFrame* frame)
     if (!oldFrame->host())
         return false;
 
-    // The frame being swapped in should not have a Frame associated
-    // with it yet.
-    ASSERT(!toCoreFrame(frame));
-
     if (m_parent) {
         if (m_parent->m_firstChild == this)
             m_parent->m_firstChild = frame;
@@ -78,7 +74,13 @@ bool WebFrame::swap(WebFrame* frame)
     // increments of connected subframes.
     FrameOwner* owner = oldFrame->owner();
     oldFrame->disconnectOwnerElement();
-    if (frame->isWebLocalFrame()) {
+    if (toCoreFrame(frame)) {
+        FrameOwner* oldOwner = toCoreFrame(frame)->owner();
+        toCoreFrame(frame)->setOwner(owner);
+        if (owner->isLocal())
+            toHTMLFrameOwnerElement(owner)->setContentFrame(*toCoreFrame(frame));
+        delete oldOwner;
+    } else if (frame->isWebLocalFrame()) {
         toWebLocalFrameImpl(frame)->initializeCoreFrame(oldFrame->host(), owner, oldFrame->tree().name(), nullAtom);
     } else {
         toWebRemoteFrameImpl(frame)->initializeCoreFrame(oldFrame->host(), owner, oldFrame->tree().name());
@@ -143,6 +145,11 @@ void WebFrame::removeChild(WebFrame* child)
     toCoreFrame(this)->tree().invalidateScopedChildCount();
 }
 
+void WebFrame::setParent(WebFrame* parent)
+{
+    m_parent = parent;
+}
+
 WebFrame* WebFrame::parent() const
 {
     return m_parent;