add ability to stop chained urls r=sspitzer part of work for 73833

mailnews/base/public/nsIMsgWindow.idl

@@ -49,7 +49,13 @@ interface nsIMsgWindow : nsISupports {
     readonly attribute nsIPrompt promptDialog;
     readonly attribute nsIAuthPrompt authPromptDialog;
     attribute wstring mailCharacterSet;
-	
+
+  /* has a running url been stopped? If you care about checking 
+      this flag, you need to clear it before you start your operation since 
+      there's no convenient place to clear it.
+  */
+  attribute boolean stopped;
+  	
 	void SetDOMWindow(in nsIDOMWindowInternal window);
 	void StopUrls();
 

mailnews/base/src/nsMsgWindow.cpp

@@ -63,6 +63,7 @@ NS_IMPL_THREADSAFE_ISUPPORTS3(nsMsgWindow,
 
 nsMsgWindow::nsMsgWindow()
 {
+  m_stopped = PR_FALSE;
   NS_INIT_ISUPPORTS();
 }
 
@@ -340,6 +341,7 @@ NS_IMETHODIMP nsMsgWindow::SetDOMWindow(nsIDOMWindowInternal *aWindow)
 
 NS_IMETHODIMP nsMsgWindow::StopUrls()
 {
+  m_stopped = PR_TRUE;
   nsCOMPtr<nsIDocShell> docShell;
   GetRootDocShell(getter_AddRefs(docShell));
   if (docShell)
@@ -553,3 +555,5 @@ nsMsgWindow::DisplayHTMLInMessagePane(const PRUnichar *title, const PRUnichar *b
 
     return NS_OK;
 }
+
+NS_IMPL_GETSET(nsMsgWindow, Stopped, PRBool, m_stopped);

mailnews/base/src/nsMsgWindow.h

@@ -61,7 +61,7 @@ protected:
   nsWeakPtr mMessageWindowDocShellWeak;
 
   nsString mMailCharacterSet;
-
+  PRBool    m_stopped;
   // small helper function used to optimize our use of a weak reference
   // on the message window docshell. Under no circumstances should you be holding on to
   // the docshell returned here outside the scope of your routine.