File system provider.

chrome/renderer/resources/extensions/file_system_provider_custom_bindings.js

Index: chrome/renderer/resources/extensions/file_system_provider_custom_bindings.js
diff --git a/chrome/renderer/resources/extensions/file_system_provider_custom_bindings.js b/chrome/renderer/resources/extensions/file_system_provider_custom_bindings.js
index 5f19793ba9a034ef292ab1840c1cc6d957f93c55..1d0e4e4421e1a1f2264e59780e1b237e3a58f56d 100644
--- a/chrome/renderer/resources/extensions/file_system_provider_custom_bindings.js
+++ b/chrome/renderer/resources/extensions/file_system_provider_custom_bindings.js
@@ -11,21 +11,29 @@ var GetDOMError = fileSystemProviderNatives.GetDOMError;
 binding.registerCustomHook(function(bindingsAPI) {
   var apiFunctions = bindingsAPI.apiFunctions;
 
+  apiFunctions.setUpdateArgumentsPostValidate('mount', function() {
+    // Hold onto the error callback or something.
+  });
+
   apiFunctions.setCustomCallback(
     'mount',
     function(name, request, response) {
       var domError = null;
       var fileSystemId = null;
       if (response) {
-        // Convert a Dictionary to a DomError.
-        domError = GetDOMError(response[0].name, response[0].message);
-        fileSystemId = response[1]
+        fileSystemId = response[0]
+        if (reponse[1]) {
+          domError = GetDOMError(response[1].name, response[1].message);
+          response.length = 1;
+        }
       }
 
-      if (request.callback) {
-        request.callback(domError, fileSystemId);
-        request.callback = null;
-      }
+      var successCallback = request.callback;
+      delete request.callback;
+      if (domError && request.failureCallback)
+        request.failureCallback(domError);
+      if (!domError && successCallback)
+        successCallback(fileSystemId)
     });
 });