diff --git a/mozilla/docshell/base/nsWebShell.cpp b/mozilla/docshell/base/nsWebShell.cpp
index 82743ac53e4..1bb88bd6edb 100644
--- a/mozilla/docshell/base/nsWebShell.cpp
+++ b/mozilla/docshell/base/nsWebShell.cpp
@@ -241,6 +241,8 @@ public:
                          PRBool aVisible,
                          nsIWebShell *&aNewWebShell);
   NS_IMETHOD CanCreateNewWebShell(PRBool& aResult);
+  NS_IMETHOD ChildShellAdded(nsIWebShell* aChildShell, nsIContent* frameNode, PRBool& aResult);
+
   NS_IMETHOD SetNewWebShellInfo(const nsString& aName, const nsString& anURL, 
                                 nsIWebShell* aOpenerShell, PRUint32 aChromeMask,
                                 nsIWebShell** aNewShell);
@@ -1903,6 +1905,16 @@ nsWebShell::CanCreateNewWebShell(PRBool& aResult)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsWebShell::ChildShellAdded(nsIWebShell* aChildShell, nsIContent* frameNode, PRBool& aResult)
+{
+  aResult = PR_FALSE;
+  if (nsnull != mContainer) {
+    return mContainer->ChildShellAdded(aChildShell, frameNode, aResult);
+  }
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsWebShell::SetNewWebShellInfo(const nsString& aName, const nsString& anURL, 
                                 nsIWebShell* aOpenerShell, PRUint32 aChromeMask,
diff --git a/mozilla/webshell/public/nsIWebShell.h b/mozilla/webshell/public/nsIWebShell.h
index 730897f25a8..8372d4552f6 100644
--- a/mozilla/webshell/public/nsIWebShell.h
+++ b/mozilla/webshell/public/nsIWebShell.h
@@ -34,6 +34,7 @@ class nsIDocumentLoaderObserver;
 class nsIWebShell;
 class nsIWebShellContainer;
 class nsIPref;
+class nsIContent;
 
 // Interface ID for nsIWebShell
 #define NS_IWEB_SHELL_IID \
@@ -102,8 +103,9 @@ public:
   
   NS_IMETHOD FindWebShellWithName(const PRUnichar* aName,
                                   nsIWebShell*& aResult) = 0;
-
   
+  NS_IMETHOD ChildShellAdded(nsIWebShell* aChildShell, nsIContent* frameNode, PRBool& aResult) = 0;
+
   /**
    * Notify the WebShellContainer that a contained webshell is
    * offering focus (for example if it finshed tabbing through its
diff --git a/mozilla/webshell/src/nsWebShell.cpp b/mozilla/webshell/src/nsWebShell.cpp
index 82743ac53e4..1bb88bd6edb 100644
--- a/mozilla/webshell/src/nsWebShell.cpp
+++ b/mozilla/webshell/src/nsWebShell.cpp
@@ -241,6 +241,8 @@ public:
                          PRBool aVisible,
                          nsIWebShell *&aNewWebShell);
   NS_IMETHOD CanCreateNewWebShell(PRBool& aResult);
+  NS_IMETHOD ChildShellAdded(nsIWebShell* aChildShell, nsIContent* frameNode, PRBool& aResult);
+
   NS_IMETHOD SetNewWebShellInfo(const nsString& aName, const nsString& anURL, 
                                 nsIWebShell* aOpenerShell, PRUint32 aChromeMask,
                                 nsIWebShell** aNewShell);
@@ -1903,6 +1905,16 @@ nsWebShell::CanCreateNewWebShell(PRBool& aResult)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsWebShell::ChildShellAdded(nsIWebShell* aChildShell, nsIContent* frameNode, PRBool& aResult)
+{
+  aResult = PR_FALSE;
+  if (nsnull != mContainer) {
+    return mContainer->ChildShellAdded(aChildShell, frameNode, aResult);
+  }
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsWebShell::SetNewWebShellInfo(const nsString& aName, const nsString& anURL, 
                                 nsIWebShell* aOpenerShell, PRUint32 aChromeMask,
diff --git a/mozilla/webshell/tests/viewer/nsBrowserWindow.cpp b/mozilla/webshell/tests/viewer/nsBrowserWindow.cpp
index d4798bdb174..4c470186d0f 100644
--- a/mozilla/webshell/tests/viewer/nsBrowserWindow.cpp
+++ b/mozilla/webshell/tests/viewer/nsBrowserWindow.cpp
@@ -1750,6 +1750,14 @@ nsBrowserWindow::CanCreateNewWebShell(PRBool& aResult)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsBrowserWindow::ChildShellAdded(nsIWebShell* aChildShell, nsIContent* frameNode, PRBool& aResult)
+{
+  aResult = PR_FALSE; // We don't ever care about handling this.
+  return NS_OK;
+}
+
+
 NS_IMETHODIMP
 nsBrowserWindow::SetNewWebShellInfo(const nsString& aName, const nsString& anURL, 
                                 nsIWebShell* aOpenerShell, PRUint32 aChromeMask,
diff --git a/mozilla/webshell/tests/viewer/nsBrowserWindow.h b/mozilla/webshell/tests/viewer/nsBrowserWindow.h
index 1a579642b6f..64fc68c04b9 100644
--- a/mozilla/webshell/tests/viewer/nsBrowserWindow.h
+++ b/mozilla/webshell/tests/viewer/nsBrowserWindow.h
@@ -107,6 +107,7 @@ public:
                          PRBool aVisible,
                          nsIWebShell *&aNewWebShell);
   NS_IMETHOD CanCreateNewWebShell(PRBool& aResult);
+  NS_IMETHOD ChildShellAdded(nsIWebShell* aChildShell, nsIContent* frameNode, PRBool& aResult);
   NS_IMETHOD SetNewWebShellInfo(const nsString& aName, const nsString& anURL, 
                                 nsIWebShell* aOpenerShell, PRUint32 aChromeMask,
                                 nsIWebShell** aNewShell);
diff --git a/mozilla/webshell/tests/viewer/nsXPBaseWindow.cpp b/mozilla/webshell/tests/viewer/nsXPBaseWindow.cpp
index 683928cb30e..50ac4116865 100644
--- a/mozilla/webshell/tests/viewer/nsXPBaseWindow.cpp
+++ b/mozilla/webshell/tests/viewer/nsXPBaseWindow.cpp
@@ -568,6 +568,13 @@ nsXPBaseWindow::CanCreateNewWebShell(PRBool& aResult)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsXPBaseWindow::ChildShellAdded(nsIWebShell* aChildShell, nsIContent* frameNode, PRBool& aResult)
+{
+  aResult = PR_FALSE;
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsXPBaseWindow::SetNewWebShellInfo(const nsString& aName, const nsString& anURL, 
                                 nsIWebShell* aOpenerShell, PRUint32 aChromeMask,
diff --git a/mozilla/webshell/tests/viewer/nsXPBaseWindow.h b/mozilla/webshell/tests/viewer/nsXPBaseWindow.h
index 3e11ccd4244..a0b716f1d93 100644
--- a/mozilla/webshell/tests/viewer/nsXPBaseWindow.h
+++ b/mozilla/webshell/tests/viewer/nsXPBaseWindow.h
@@ -98,6 +98,7 @@ public:
                          PRBool aVisible,
                          nsIWebShell *&aNewWebShell);
   NS_IMETHOD CanCreateNewWebShell(PRBool& aResult);
+  NS_IMETHOD ChildShellAdded(nsIWebShell* aChildShell, nsIContent* frameNode, PRBool& aResult);
   NS_IMETHOD SetNewWebShellInfo(const nsString& aName, const nsString& anURL, 
                                 nsIWebShell* aOpenerShell, PRUint32 aChromeMask,
                                 nsIWebShell** aNewShell);