Componentize //chrome/browser/prefs/tracked.

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 fc7d9811b82d94648ee19f365389265c3e4c6833..830a6976ddc5fc27382d5c13220f7c5d73372dde 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -1161,10 +1161,6 @@ const char kFullscreenAllowed[] = "fullscreen.allowed";
 const char kLocalDiscoveryNotificationsEnabled[] =
     "local_discovery.notifications_enabled";
 
-// A timestamp (stored in base::Time::ToInternalValue format) of the last time
-// a preference was reset.
-const char kPreferenceResetTime[] = "prefs.preference_reset_time";
-
 // How many Service Workers are registered with the Push API (could be zero).
 const char kPushMessagingRegistrationCount[] =
     "gcm.push_messaging_registration_count";