Added hasSubstitutions for Hyatt & chrome protocol.

netwerk/protocol/res/public/nsIResProtocolHandler.idl

@@ -71,4 +71,9 @@ interface nsIResProtocolHandler : nsIProtocolHandler
      * thread-safety concerns.
      */
     nsISupportsArray getSubstitutions(in string root);
+
+    /**
+     * Returns true if substitutions are already defined for the specified root.
+     */
+    boolean hasSubstitutions(in string root);
 };

netwerk/protocol/res/src/nsResProtocolHandler.cpp

@@ -379,4 +379,12 @@ nsResProtocolHandler::GetSubstitutions(const char *root, nsISupportsArray* *resu
     return NS_OK;
 }
 
+NS_IMETHODIMP
+nsResProtocolHandler::HasSubstitutions(const char *root, PRBool *result)
+{
+    nsStringKey key(root);
+    *result = mSubstitutions.Exists(&key);
+    return NS_OK;
+}
+
 ////////////////////////////////////////////////////////////////////////////////