Disabled transparency for header bars on the signin screen.

ash/wm/window_properties.cc

Index: ash/wm/window_properties.cc
diff --git a/ash/wm/window_properties.cc b/ash/wm/window_properties.cc
index 56aa398b3bf8e01a6e8010d0cb7c44453ccd1cec..874f030a0b802ce18940401fb2dabd7c48de59e9 100644
--- a/ash/wm/window_properties.cc
+++ b/ash/wm/window_properties.cc
@@ -22,6 +22,7 @@ namespace internal {
 DEFINE_OWNED_WINDOW_PROPERTY_KEY(ash::internal::AlwaysOnTopController,
                                  kAlwaysOnTopControllerKey,
                                  NULL);
+DEFINE_WINDOW_PROPERTY_KEY(bool, kIgnoreSoloWindowFramePainterPolicy, false);
 DEFINE_WINDOW_PROPERTY_KEY(bool, kIgnoredByShelfKey, false);
 DEFINE_WINDOW_PROPERTY_KEY(
     ui::WindowShowState, kRestoreShowStateKey, ui::SHOW_STATE_DEFAULT);