Tracing for NavigationHandle lifetime and state.

chrome/browser/chromeos/login/signin/merge_session_navigation_throttle.h

 // Copyright 2015 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_CHROMEOS_LOGIN_SIGNIN_MERGE_SESSION_NAVIGATION_THROTTLE_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_SIGNIN_MERGE_SESSION_NAVIGATION_THROTTLE_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 11 matching lines @@
  public:
   static std::unique_ptr<content::NavigationThrottle> Create(
       content::NavigationHandle* handle);
   ~MergeSessionNavigationThrottle() override;
 
  private:
   explicit MergeSessionNavigationThrottle(content::NavigationHandle* handle);
 
   // content::NavigationThrottle implementation:
   content::NavigationThrottle::ThrottleCheckResult WillStartRequest() override;
+  const char* GetNameForLogging() override;
 
   // MergeSessionLoadPage callback.
   void OnBlockingPageComplete();
 
   base::WeakPtrFactory<MergeSessionNavigationThrottle> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MergeSessionNavigationThrottle);
 };
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SIGNIN_MERGE_SESSION_NAVIGATION_THROTTLE_H_