Detach old frame on WebFrame::swap.

Source/core/frame/LocalFrame.cpp

Index: Source/core/frame/LocalFrame.cpp
diff --git a/Source/core/frame/LocalFrame.cpp b/Source/core/frame/LocalFrame.cpp
index fae19d435e8f8e24232c3c16219d196c5fd06dcb..0f3fad44f8817e90ccccd9c72ca8c5547ba0855c 100644
--- a/Source/core/frame/LocalFrame.cpp
+++ b/Source/core/frame/LocalFrame.cpp
@@ -273,7 +273,7 @@ void LocalFrame::reload(FrameLoadType loadType, ClientRedirectPolicy clientRedir
     }
 }
 
-void LocalFrame::detach()
+void LocalFrame::detach(FrameDetachType type)
 {
     PluginScriptForbiddenScope forbidPluginDestructorScripting;
     // A lot of the following steps can result in the current frame being
@@ -300,7 +300,7 @@ void LocalFrame::detach()
     setView(nullptr);
     willDetachFrameHost();
     InspectorInstrumentation::frameDetachedFromParent(this);
-    Frame::detach();
+    Frame::detach(type);
 
     // Signal frame destruction here rather than in the destructor.
     // Main motivation is to avoid being dependent on its exact timing (Oilpan.)
@@ -309,6 +309,11 @@ void LocalFrame::detach()
     WeakIdentifierMap<LocalFrame>::notifyObjectDestroyed(this);
 }
 
+bool LocalFrame::prepareForCommit()
+{
+    return loader().prepareForCommit();
+}
+
 SecurityContext* LocalFrame::securityContext() const
 {
     return document();