Chromium does not throw the exception message by calling NPN_SetException from NPAPI plugin

content/common/npobject_util.cc

Index: content/common/npobject_util.cc
===================================================================
--- content/common/npobject_util.cc	(revision 109161)
+++ content/common/npobject_util.cc	(working copy)
@@ -87,8 +87,19 @@
   std::string message_str(message);
   if (IsPluginProcess()) {
     NPChannelBase* renderer_channel = NPChannelBase::GetCurrentChannel();
-    if (renderer_channel)
-      renderer_channel->Send(new PluginHostMsg_SetException(message_str));
+    if (renderer_channel) {
+      if (obj->_class != NPObjectProxy::npclass()) {
+        int route_id = MSG_ROUTING_NONE;
+        // Determine the route id of NPObjectProxy instance in renderer process
+        // It is the same as the route id of NPObjectStub instance in plugin
+        // process.
+        route_id = renderer_channel->GetExistingRouteForNPObjectStub(obj);
+        renderer_channel->Send(new NPObjectMsg_SetException(route_id,
+                                                            message_str));
+      } else {
+        renderer_channel->Send(new PluginHostMsg_SetException(message_str));
+      }
+    }
   } else {
     WebBindings::setException(obj, message_str.c_str());
   }