Add laser pointer palette code w/o laser pointer impelmentation

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

Index: ash/common/system/chromeos/palette/palette_tool.cc
diff --git a/ash/common/system/chromeos/palette/palette_tool.cc b/ash/common/system/chromeos/palette/palette_tool.cc
index f133468d9d394e06049ddaee0da05d883ec208c8..9e90e34b0183315bcb8bfd5161c8ce68a0ee7036 100644
--- a/ash/common/system/chromeos/palette/palette_tool.cc
+++ b/ash/common/system/chromeos/palette/palette_tool.cc
@@ -5,12 +5,15 @@
 #include "ash/common/system/chromeos/palette/palette_tool.h"
 
 #include "ash/common/system/chromeos/palette/palette_tool_manager.h"
+#include "ash/common/system/chromeos/palette/tools/laser_pointer_mode.h"
 #include "ui/gfx/vector_icons_public.h"
 
 namespace ash {
 
 // static
-void PaletteTool::RegisterToolInstances(PaletteToolManager* tool_manager) {}
+void PaletteTool::RegisterToolInstances(PaletteToolManager* tool_manager) {
+  tool_manager->AddTool(base::WrapUnique(new LaserPointerMode(tool_manager)));
+}
 
 PaletteTool::PaletteTool(Delegate* delegate) : delegate_(delegate) {}