Revert 146038 as it might have broken chromeos browser_tests - Make eventArgumentMassagers asynchro…

chrome/renderer/extensions/chrome_v8_context_set.cc

Index: chrome/renderer/extensions/chrome_v8_context_set.cc
===================================================================
--- chrome/renderer/extensions/chrome_v8_context_set.cc	(revision 146077)
+++ chrome/renderer/extensions/chrome_v8_context_set.cc	(working copy)
@@ -145,5 +145,15 @@
     v8::Handle<v8::Value> retval;
     (*it)->CallChromeHiddenMethod(
         method_name, v8_arguments.size(), &v8_arguments[0], &retval);
+    // In debug, the js will validate the event parameters and return a
+    // string if a validation error has occured.
+    // TODO(rafaelw): Consider only doing this check if function_name ==
+    // "Event.dispatchJSON".
+#ifndef NDEBUG
+    if (!retval.IsEmpty() && !retval->IsUndefined()) {
+      std::string error = *v8::String::AsciiValue(retval);
+      DCHECK(false) << error;
+    }
+#endif
   }
 }