Eliminate all code related to the AutomaticProfileResetter.

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 14bb5b5cb8feda6963c937a6d4da13d47fd1c549..de5e3cc445550312325d4ec2538e4eda7aba052d 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -1195,9 +1195,12 @@ const char kLocalDiscoveryNotificationsEnabled[] =
 // a preference was reset.
 const char kPreferenceResetTime[] = "prefs.preference_reset_time";
 
+// OBSOLETE. The AutomaticProfileResetter service has been removed. We keep the
+// name here for now so we can clear out legacy values.
 // String that indicates if the Profile Reset prompt has already been shown to
 // the user. Used both in user preferences and local state, in the latter, it is
 // actually a dictionary that maps profile keys to before-mentioned strings.
+// TODO(engedy): Remove this and usages in M42 or later. See crbug.com/398813.
 const char kProfileResetPromptMemento[] = "profile.reset_prompt_memento";
 
 // The GCM channel's enabled state.