Tracing for NavigationHandle lifetime and state.

chrome/browser/page_load_metrics/metrics_navigation_throttle.cc

 // Copyright 2016 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 "chrome/browser/page_load_metrics/metrics_navigation_throttle.h"
 
 #include "base/memory/ptr_util.h"
 #include "chrome/browser/page_load_metrics/metrics_web_contents_observer.h"
 #include "content/public/browser/navigation_handle.h"
 
@@ skipping 20 matching lines @@
 content::NavigationThrottle::ThrottleCheckResult
 MetricsNavigationThrottle::WillProcessResponse() {
   MetricsWebContentsObserver* observer =
       MetricsWebContentsObserver::FromWebContents(
           navigation_handle()->GetWebContents());
   if (observer)
     observer->WillProcessNavigationResponse(navigation_handle());
   return content::NavigationThrottle::PROCEED;
 }
 
+const char* MetricsNavigationThrottle::GetNameForLogging() {
+  return "MetricsNavigationThrottle";
+}
+
 MetricsNavigationThrottle::MetricsNavigationThrottle(
     content::NavigationHandle* handle)
     : content::NavigationThrottle(handle) {}
 
 }  // namespace page_load_metrics