Reland: Show message center on lock screen

ui/message_center/fake_message_center.cc

Index: ui/message_center/fake_message_center.cc
diff --git a/ui/message_center/fake_message_center.cc b/ui/message_center/fake_message_center.cc
index acfe78974c31a8cbdf212616bb7c3098a1c48336..1900b0e65f6473447217998775dd441c10efd0a9 100644
--- a/ui/message_center/fake_message_center.cc
+++ b/ui/message_center/fake_message_center.cc
@@ -42,6 +42,10 @@ bool FakeMessageCenter::IsQuietMode() const {
   return false;
 }
 
+bool FakeMessageCenter::IsLockedState() const {
+  return false;
+}
+
 bool FakeMessageCenter::HasClickedListener(const std::string& id) {
   return false;
 }
@@ -121,6 +125,8 @@ NotifierSettingsProvider* FakeMessageCenter::GetNotifierSettingsProvider() {
 void FakeMessageCenter::SetQuietMode(bool in_quiet_mode) {
 }
 
+void FakeMessageCenter::SetLockedState(bool locked) {}
+
 void FakeMessageCenter::EnterQuietModeWithExpire(
     const base::TimeDelta& expires_in) {
 }