Add the "virtual" keyword on method overrides that are missing it.

chrome/plugin/npobject_proxy.cc

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/plugin/npobject_proxy.h"
 
 #include "chrome/common/plugin_messages.h"
 #include "chrome/plugin/npobject_util.h"
 #include "chrome/plugin/plugin_channel.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebBindings.h"
@@ skipping 28 matching lines @@
 
   // Wrapper exists only for NPObjects that we had created.
   if (&npclass_proxy_ == object->_class) {
     NPObjectWrapper* wrapper = reinterpret_cast<NPObjectWrapper*>(object);
     proxy = wrapper->proxy;
   }
 
   return proxy;
 }
 
+NPObject* NPObjectProxy::GetUnderlyingNPObject() {
+  return NULL;
+}
+
+IPC::Channel::Listener* NPObjectProxy::GetChannelListener() {
+  return static_cast<IPC::Channel::Listener*>(this);
+}
+
 NPObjectProxy::NPObjectProxy(
     PluginChannelBase* channel,
     int route_id,
     gfx::NativeViewId containing_window,
     const GURL& page_url)
     : channel_(channel),
       route_id_(route_id),
       containing_window_(containing_window),
       page_url_(page_url) {
   channel_->AddRoute(route_id, this, this);
@@ skipping 423 matching lines @@
   proxy->Send(msg);
   // Send may delete proxy.
   proxy = NULL;
   if (!result)
     return false;
 
   CreateNPVariant(
       result_param, channel.get(), result_var, containing_window, page_url);
   return true;
 }