Gather stability prefs into managing objects.

components/metrics/clean_exit_beacon.cc

Index: components/metrics/clean_exit_beacon.cc
diff --git a/components/metrics/clean_exit_beacon.cc b/components/metrics/clean_exit_beacon.cc
index 8868e0f99a02609963ec0d54c3b5e7a297579360..4bca5d1c39594ba242d8c64367da134a42226059 100644
--- a/components/metrics/clean_exit_beacon.cc
+++ b/components/metrics/clean_exit_beacon.cc
@@ -7,6 +7,7 @@
 #include "base/logging.h"
 #include "build/build_config.h"
 #include "components/metrics/metrics_pref_names.h"
+#include "components/prefs/pref_registry_simple.h"
 #include "components/prefs/pref_service.h"
 
 #if defined(OS_WIN)
@@ -62,6 +63,11 @@ CleanExitBeacon::CleanExitBeacon(const base::string16& backup_registry_key,
 CleanExitBeacon::~CleanExitBeacon() {
 }
 
+// static
+void CleanExitBeacon::RegisterPrefs(PrefRegistrySimple* registry) {
+  registry->RegisterBooleanPref(prefs::kStabilityExitedCleanly, true);
+}
+
 void CleanExitBeacon::WriteBeaconValue(bool value) {
   local_state_->SetBoolean(prefs::kStabilityExitedCleanly, value);