Auto open and close the palette on an eject event.

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

Index: ash/common/system/chromeos/palette/palette_tray.cc
diff --git a/ash/common/system/chromeos/palette/palette_tray.cc b/ash/common/system/chromeos/palette/palette_tray.cc
index 1a13c9c4ba9ffe9af7800b322415cdbfa9d066d7..9b5535d11f67d5005cc012c604111b3128a276c0 100644
--- a/ash/common/system/chromeos/palette/palette_tray.cc
+++ b/ash/common/system/chromeos/palette/palette_tray.cc
@@ -4,10 +4,12 @@
 
 #include "ash/common/system/chromeos/palette/palette_tray.h"
 
+#include "ash/common/palette_delegate.h"
 #include "ash/common/shelf/shelf_constants.h"
 #include "ash/common/shelf/wm_shelf.h"
 #include "ash/common/shelf/wm_shelf_util.h"
 #include "ash/common/shell_window_ids.h"
+#include "ash/common/system/chromeos/palette/eject_controller.h"
 #include "ash/common/system/chromeos/palette/palette_tool_manager.h"
 #include "ash/common/system/chromeos/palette/palette_utils.h"
 #include "ash/common/system/tray/system_tray_delegate.h"
@@ -22,6 +24,7 @@
 #include "grit/ash_strings.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
+#include "ui/events/devices/stylus_state.h"
 #include "ui/gfx/paint_vector_icon.h"
 #include "ui/views/controls/image_view.h"
 #include "ui/views/controls/label.h"
@@ -121,6 +124,9 @@ class TitleView : public views::View, public views::ButtonListener {
 PaletteTray::PaletteTray(WmShelf* wm_shelf)
     : TrayBackgroundView(wm_shelf),
       palette_tool_manager_(new PaletteToolManager(this)) {
+  eject_controller_.reset(new EjectController(
+      base::Bind(&PaletteTray::OnStylusEject, base::Unretained(this))));
+
   PaletteTool::RegisterToolInstances(palette_tool_manager_.get());
 
   SetContentsBackground();
@@ -210,7 +216,7 @@ void PaletteTray::SessionStateChanged(
 }
 
 void PaletteTray::ClickedOutsideBubble() {
-  HidePalette();
+  bubble_.reset();
 }
 
 base::string16 PaletteTray::GetAccessibleNameForTray() {
@@ -315,6 +321,17 @@ void PaletteTray::UpdateTrayIcon() {
   icon_->SetImage(CreateVectorIcon(icon, kShelfIconSize, kShelfIconColor));
 }
 
+void PaletteTray::OnStylusEject(ui::StylusState stylus_state) {
+  if (!WmShell::Get()->palette_delegate()->ShouldAutoOpenPalette())
+    return;
+
+  if (stylus_state == ui::StylusState::REMOVED && !bubble_)
+    OpenBubble();
+
+  if (stylus_state == ui::StylusState::INSERTED && bubble_)

[oshima, 2016/08/24 23:38:50]

nit: else if?

You may keep it if you prefer this way though. 

[jdufault, 2016/08/24 23:54:07]

Done.

+    bubble_.reset();
+}
+
 void PaletteTray::UpdateIconVisibility() {
   if (!IsPaletteEnabled())
     return;