work for bug #38374 helperApps.rdf is now mimeTypes.rdf. use the file locator to get the mimeTypes file. fix the unix implementation of nsOSHelperAppService.cpp to go to the base class to determine what application to launch. r=mscott

uriloader/exthandler/nsExternalHelperAppService.cpp

@@ -78,12 +78,12 @@ nsresult nsExternalHelperAppService::Init()
   nsCOMPtr<nsIFileLocator> locator = do_GetService(NS_FILELOCATOR_PROGID, &rv);
   NS_ENSURE_SUCCESS(rv, rv);
   
-  nsCOMPtr<nsIFileSpec> dataFilesDir;
-  rv = locator->GetFileLocation(nsSpecialFileSpec::App_UserProfileDirectory50,
-                                getter_AddRefs(dataFilesDir));
-  dataFilesDir->AppendRelativeUnixPath("test.rdf");
+  nsCOMPtr<nsIFileSpec> mimeTypesFile;
+  rv = locator->GetFileLocation(nsSpecialFileSpec::App_UsersMimeTypes50,
+                                getter_AddRefs(mimeTypesFile));
   nsXPIDLCString url;
-  dataFilesDir->GetURLString(getter_Copies(url));
+  rv = mimeTypesFile->GetURLString(getter_Copies(url));
+  NS_ENSURE_SUCCESS(rv, rv);
 
   rv = remoteDS->Init(url);
   NS_ENSURE_SUCCESS(rv, rv);