Rename DesktopEngagement* to DesktopSessionDuration*.

chrome/browser/android/metrics/uma_session_stats.cc

Index: chrome/browser/android/metrics/uma_session_stats.cc
diff --git a/chrome/browser/android/metrics/uma_session_stats.cc b/chrome/browser/android/metrics/uma_session_stats.cc
index 67329420cdc588780e4c428d2b3d718bc9ce3faa..b31d139967abe019de67073cab2948743ef7120f 100644
--- a/chrome/browser/android/metrics/uma_session_stats.cc
+++ b/chrome/browser/android/metrics/uma_session_stats.cc
@@ -65,7 +65,7 @@ void UmaSessionStats::UmaEndSession(JNIEnv* env,
     base::TimeDelta duration = base::TimeTicks::Now() - session_start_time_;
 
     // Note: This metric is recorded separately on desktop in
-    // DesktopEngagementService::EndSession.
+    // DesktopSessionService::EndSession.
     UMA_HISTOGRAM_LONG_TIMES("Session.TotalDuration", duration);
 
     DCHECK(g_browser_process);