Added a CanHandleContentType to identify if a given instantiated docShell can handle the requested document type.

git-svn-id: svn://10.0.0.236/trunk@51841 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/docshell/html/nsHTMLDocShell.h

@@ -31,6 +31,9 @@ class nsHTMLDocShell : public nsDocShellBase, public nsIHTMLDocShell
 public:
    NS_DECL_ISUPPORTS
 
+   NS_IMETHOD CanHandleContentType(const PRUnichar* contentType, PRBool* canHandle);
+
+
    NS_DECL_NSIHTMLDOCSHELL
 
    static NS_METHOD Create(nsISupports* aOuter, const nsIID& aIID, void** ppv);