Move NPAPI test plugin to content/test/plugin.

content/test/plugin/plugin_arguments_test.h

Index: content/test/plugin/plugin_arguments_test.h
===================================================================
--- content/test/plugin/plugin_arguments_test.h	(revision 0)
+++ content/test/plugin/plugin_arguments_test.h	(working copy)
@@ -2,11 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef WEBKIT_PLUGINS_NPAPI_TEST_PLUGIN_ARGUMENTS_TEST_H_
-#define WEBKIT_PLUGINS_NPAPI_TEST_PLUGIN_ARGUMENTS_TEST_H_
+#ifndef CONTENT_TEST_PLUGIN_PLUGIN_ARGUMENTS_TEST_H_
+#define CONTENT_TEST_PLUGIN_PLUGIN_ARGUMENTS_TEST_H_
 
 #include "base/compiler_specific.h"
-#include "webkit/plugins/npapi/test/plugin_test.h"
+#include "content/test/plugin/plugin_test.h"
 
 namespace NPAPIClient {
 
@@ -41,4 +41,4 @@
 
 }  // namespace NPAPIClient
 
-#endif  // WEBKIT_PLUGINS_NPAPI_TEST_PLUGIN_ARGUMENTS_TEST_H_
+#endif  // CONTENT_TEST_PLUGIN_PLUGIN_ARGUMENTS_TEST_H_