Add an experiment for the default browser infobar on Windows 10

chrome/browser/shell_integration.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 CHROME_BROWSER_SHELL_INTEGRATION_H_
 #define CHROME_BROWSER_SHELL_INTEGRATION_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 199 matching lines @@
   bool check_default_should_report_success_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(DefaultWebClientWorker);
 };
 
 // Worker for checking and setting the default browser.
 class DefaultBrowserWorker : public DefaultWebClientWorker {
  public:
   explicit DefaultBrowserWorker(const DefaultWebClientWorkerCallback& callback);
 
- private:
+ protected:
   ~DefaultBrowserWorker() override;
 
+ private:
   // Check if Chrome is the default browser.
   DefaultWebClientState CheckIsDefaultImpl() override;
 
   // Set Chrome as the default browser.
   void SetAsDefaultImpl(const base::Closure& on_finished_callback) override;
 
   DISALLOW_COPY_AND_ASSIGN(DefaultBrowserWorker);
 };
 
 // Worker for checking and setting the default client application
@@ skipping 18 matching lines @@
   void SetAsDefaultImpl(const base::Closure& on_finished_callback) override;
 
   std::string protocol_;
 
   DISALLOW_COPY_AND_ASSIGN(DefaultProtocolClientWorker);
 };
 
 }  // namespace shell_integration
 
 #endif  // CHROME_BROWSER_SHELL_INTEGRATION_H_