arc: Logging ARC data removal reasons

chrome/browser/chromeos/arc/arc_session_manager.h

Index: chrome/browser/chromeos/arc/arc_session_manager.h
diff --git a/chrome/browser/chromeos/arc/arc_session_manager.h b/chrome/browser/chromeos/arc/arc_session_manager.h
index 29f9384a488b218123fdcd9d50ba6e0550b53c04..36e382ca9a658bb5eec94b1ff6530f9f840fa378 100644
--- a/chrome/browser/chromeos/arc/arc_session_manager.h
+++ b/chrome/browser/chromeos/arc/arc_session_manager.h
@@ -203,7 +203,8 @@ class ArcSessionManager : public ArcSessionObserver,
   void StopAndEnableArc();
 
   // Removes the data if ARC is stopped. Otherwise, queue to remove the data
-  // on ARC is stopped.
+  // on ARC is stopped. A log statement with the removal reason must be added
+  // prior to calling RemoveArcData().
   void RemoveArcData();
 
   ArcSupportHost* support_host() { return support_host_.get(); }