Auto open and close the palette on an eject event.

ash/common/system/chromeos/palette/palette_tray.h

Index: ash/common/system/chromeos/palette/palette_tray.h
diff --git a/ash/common/system/chromeos/palette/palette_tray.h b/ash/common/system/chromeos/palette/palette_tray.h
index 0cb60c1ba38c64e9ca68970bbc619ce27a97825c..57fe0ff037c894bf8caac5fd0e18a1e31d2392f5 100644
--- a/ash/common/system/chromeos/palette/palette_tray.h
+++ b/ash/common/system/chromeos/palette/palette_tray.h
@@ -14,6 +14,7 @@
 #include "ash/common/system/chromeos/palette/palette_tool_manager.h"
 #include "ash/common/system/tray/tray_background_view.h"
 #include "base/macros.h"
+#include "ui/events/devices/input_device_manager.h"
 
 namespace views {
 class ImageView;
@@ -85,6 +86,9 @@ class ASH_EXPORT PaletteTray : public TrayBackgroundView,
   // Sets the icon to visible if the palette can be used.
   void UpdateIconVisibility();
 
+  // Called when a stylus inserted or removed event is received.
+  void OnStylusStateChanged(ui::StylusState stylus_state);
+
   bool OpenBubble();
   void AddToolsToView(views::View* host);