CONTENT_EXPORT is missing for ContentMainRunner class

content/public/app/content_main_runner.h

 // Copyright (c) 2012 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.
 
 #ifndef CONTENT_PUBLIC_APP_CONTENT_MAIN_RUNNER_H_
 #define CONTENT_PUBLIC_APP_CONTENT_MAIN_RUNNER_H_
 
+#include "build/build_config.h"
+#include "content/common/content_export.h"
+
 namespace content {
 struct ContentMainParams;
 
 // This class is responsible for content initialization, running and shutdown.
-class ContentMainRunner {
+class CONTENT_EXPORT ContentMainRunner {
  public:
   virtual ~ContentMainRunner() {}
 
   // Create a new ContentMainRunner object.
   static ContentMainRunner* Create();
 
   // Initialize all necessary content state.
   virtual int Initialize(const ContentMainParams& params) = 0;
 
   // Perform the default run logic.
   virtual int Run() = 0;
 
   // Shut down the content state.
   virtual void Shutdown() = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_APP_CONTENT_MAIN_RUNNER_H_