Cleanup: Remove VersionUpdater::RelaunchBrowser interface method.

chrome/browser/lifetime/application_lifetime.cc

Index: chrome/browser/lifetime/application_lifetime.cc
diff --git a/chrome/browser/lifetime/application_lifetime.cc b/chrome/browser/lifetime/application_lifetime.cc
index c99bb91553c4b2dc2833f262353574168ff2169d..19fd12723278ea432ba7d93ae3c4f86534fdb26f 100644
--- a/chrome/browser/lifetime/application_lifetime.cc
+++ b/chrome/browser/lifetime/application_lifetime.cc
@@ -235,6 +235,14 @@ void AttemptRestart() {
 }
 #endif  // !defined(OS_ANDROID)
 
+void AttemptRelaunch() {
+#if defined(OS_CHROMEOS)
+  chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->RequestRestart();
+  // If running the Chrome OS build, but we're not on the device, fall through.
+#endif
+  chrome::AttemptRestart();
+}
+
 void AttemptExit() {
 #if defined(OS_CHROMEOS)
   // On ChromeOS, user exit and system exits are the same.