Add "stylus-tools" Wayland protocol.

components/exo/surface.h

Index: components/exo/surface.h
diff --git a/components/exo/surface.h b/components/exo/surface.h
index ae85eca8c69166c1086589bdda25be4a6c836a7d..0abd511378882ddf5aa8c1df77a235828638b575 100644
--- a/components/exo/surface.h
+++ b/components/exo/surface.h
@@ -200,6 +200,12 @@ class Surface : public ui::ContextFactoryObserver,
   // Returns the active contents size.
   gfx::Size content_size() const { return content_size_; }
 
+  // Returns true if the associated window is in 'stylus-only' mode.
+  bool IsStylusOnly();
+
+  // Enables 'stylus-only' mode for the associated window.
+  void SetStylusOnly();
+
   // Overridden from ui::ContextFactoryObserver:
   void OnLostResources() override;