cros: Hide stylus tools on various sign-in screens, disable active mode when inserting stylus.

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

Index: ash/common/system/chromeos/palette/palette_tool_manager.cc
diff --git a/ash/common/system/chromeos/palette/palette_tool_manager.cc b/ash/common/system/chromeos/palette/palette_tool_manager.cc
index d9a79b806079e45e7820862a2219a1e5768f5ab0..89ba99eed43ccde76c7cb8fa74b879cc5341d0d4 100644
--- a/ash/common/system/chromeos/palette/palette_tool_manager.cc
+++ b/ash/common/system/chromeos/palette/palette_tool_manager.cc
@@ -106,6 +106,12 @@ void PaletteToolManager::NotifyViewsDestroyed() {
     tool->OnViewDestroyed();
 }
 
+void PaletteToolManager::DisableActiveTool(PaletteGroup group) {
+  PaletteToolId tool_id = GetActiveTool(group);
+  if (tool_id != PaletteToolId::NONE)
+    DeactivateTool(tool_id);
+}
+
 void PaletteToolManager::EnableTool(PaletteToolId tool_id) {
   ActivateTool(tool_id);
 }