Bug 997440 - Fix some more error reporting in crashreporter tests. r=bholley

toolkit/crashreporter/test/browser/head.js

@@ -31,7 +31,13 @@ function make_fake_appdir() {
       if (prop == "UAppData") {
         return appD.clone();
       }
-      throw Components.results.NS_ERROR_FAILURE;
+      // Depending on timing we can get requests for other files.
+      // When we threw an exception here, in the world before bug 997440, this got lost
+      // because of the arbitrary JSContext being used in XPCWrappedJSClass::CallMethod.
+      // After bug 997440 this gets reported to our window and causes the tests to fail.
+      // So, we'll just dump out a message to the logs.
+      dump("WARNING: make_fake_appdir - fake nsIDirectoryServiceProvider - Unexpected getFile for: '" + prop + "'\n");
+      return null;
     },
     QueryInterface: function(iid) {
       if (iid.equals(Ci.nsIDirectoryServiceProvider) ||