Remove NPAPI test plugin

content/shell/tools/plugin/Tests/FormValue.cpp

-// Copyright 2014 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 "PluginTest.h"
-#include <string.h>
-
-extern NPNetscapeFuncs *browser;
-
-class FormValue : public PluginTest {
-public:
-    FormValue(NPP npp, const std::string& identifier)
-        : PluginTest(npp, identifier)
-    {
-    }
-    NPError NPP_GetValue(NPPVariable, void*) override;
-};
-
-NPError FormValue::NPP_GetValue(NPPVariable variable, void *value)
-{
-    if (variable == NPPVformValue) {
-        static const char formValueText[] = "Plugin form value";
-        *((void**)value) = browser->memalloc(sizeof(formValueText));
-        if (!*((void**)value))
-            return NPERR_OUT_OF_MEMORY_ERROR;
-        strncpy(*((char**)value), formValueText, sizeof(formValueText));
-        return NPERR_NO_ERROR;
-    }
-    return NPERR_GENERIC_ERROR;
-}
-
-static PluginTest::Register<FormValue> formValue("form-value");