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..5338a547f5c4bd1f717b60a19e08e3651f756e58 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;
@@ -22,6 +23,7 @@ class Widget;
 
 namespace ash {
 
+class EjectController;
 class TrayBubbleWrapper;
 class PaletteToolManager;
 
@@ -85,11 +87,15 @@ class ASH_EXPORT PaletteTray : public TrayBackgroundView,
   // Sets the icon to visible if the palette can be used.
   void UpdateIconVisibility();
 
+  // Called when a stylus eject event is received.
+  void OnStylusEject(ui::StylusState stylus_state);
+
   bool OpenBubble();
   void AddToolsToView(views::View* host);
 
   std::unique_ptr<PaletteToolManager> palette_tool_manager_;
   std::unique_ptr<TrayBubbleWrapper> bubble_;
+  std::unique_ptr<EjectController> eject_controller_;
 
   // Weak pointer, will be parented by TrayContainer for its lifetime.
   views::ImageView* icon_;