aura: Fix a couple of tooltip related bugs:

ash/shell/lock_view.cc

Index: ash/shell/lock_view.cc
diff --git a/ash/shell/lock_view.cc b/ash/shell/lock_view.cc
index 245bcee59ef77e36fc8de7644d211fb48e3c3b78..843ba6a59ccd6df6ea33f75ae1f829bf243c42fc 100644
--- a/ash/shell/lock_view.cc
+++ b/ash/shell/lock_view.cc
@@ -5,6 +5,7 @@
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/shell/example_factory.h"
+#include "ash/tooltips/tooltip_controller.h"
 #include "base/utf_string_conversions.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
@@ -68,6 +69,9 @@ void CreateLockScreen() {
   widget->SetContentsView(lock_view);
   widget->Show();
   widget->GetNativeView()->SetName("LockView");
+
+  Shell::GetInstance()->tooltip_controller()->UpdateTooltip(
+      widget->GetNativeView());
 }
 
 }  // namespace shell