Remove calls to deprecated MessageLoop methods in extensions.

extensions/renderer/script_context_set_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 <vector>
 
 #include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/extension_set.h"
 #include "extensions/common/features/feature.h"
 #include "extensions/renderer/scoped_web_frame.h"
 #include "extensions/renderer/script_context.h"
 #include "extensions/renderer/script_context_set.h"
 #include "gin/public/context_holder.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/WebKit/public/web/WebFrame.h"
 #include "v8/include/v8.h"
@@ skipping 31 matching lines @@
 
   // Test context is correctly removed.
   context_set.Remove(context);
   EXPECT_EQ(0u, context_set.size());
   EXPECT_EQ(nullptr, context_set.GetByV8Context(v8_context));
 
   // After removal, the context should be marked for destruction.
   EXPECT_FALSE(context->is_valid());
 
   // Run loop to do the actual deletion.
-  loop.RunUntilIdle();
+  base::RunLoop().RunUntilIdle();
 }
 
 }  // namespace extensions