[Extensions] Don't allow built-in extensions code to be overridden

extensions/renderer/utils_unittest.cc

 // 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 "base/strings/stringprintf.h"
 #include "extensions/renderer/module_system_test.h"
 #include "gin/dictionary.h"
 #include "grit/extensions_renderer_resources.h"
 
 namespace extensions {
 namespace {
 
 class UtilsUnittest : public ModuleSystemTest {
  private:
   void SetUp() override {
     ModuleSystemTest::SetUp();
 
     env()->RegisterModule("utils", IDR_UTILS_JS);
     env()->RegisterTestFile("utils_unittest", "utils_unittest.js");
     env()->OverrideNativeHandler("schema_registry",
-                                 "exports.GetSchema = function() {};");
+                                 "exports.$set('GetSchema', function() {});");
     env()->OverrideNativeHandler("logging",
-                                 "exports.CHECK = function() {};\n"
-                                 "exports.DCHECK = function() {};\n"
-                                 "exports.WARNING = function() {};");
+                                 "exports.$set('CHECK', function() {});\n"
+                                 "exports.$set('DCHECK', function() {});\n"
+                                 "exports.$set('WARNING', function() {});");
     env()->OverrideNativeHandler("v8_context", "");
     gin::Dictionary chrome(env()->isolate(), env()->CreateGlobal("chrome"));
     gin::Dictionary chrome_runtime(
         gin::Dictionary::CreateEmpty(env()->isolate()));
     chrome.Set("runtime", chrome_runtime);
   }
 };
 
 TEST_F(UtilsUnittest, TestNothing) {
   ExpectNoAssertionsMade();
@@ skipping 32 matching lines @@
 TEST_F(UtilsUnittest, PromiseError) {
   ModuleSystem::NativesEnabledScope natives_enabled_scope(
       env()->module_system());
   env()->module_system()->CallModuleMethod("utils_unittest",
                                            "testPromiseError");
   RunResolvedPromises();
 }
 
 }  // namespace
 }  // namespace extensions