Add "stylus-tools" Wayland protocol.

components/exo/surface.cc

Index: components/exo/surface.cc
diff --git a/components/exo/surface.cc b/components/exo/surface.cc
index d68aa04186364f6113f8e13ed4730a3f94e5829c..6f57cf5f1cf789c48a2d3559e8895ecc9502e81a 100644
--- a/components/exo/surface.cc
+++ b/components/exo/surface.cc
@@ -26,6 +26,7 @@
 #include "components/exo/surface_delegate.h"
 #include "components/exo/surface_observer.h"
 #include "third_party/khronos/GLES2/gl2.h"
+#include "ui/aura/client/aura_constants.h"
 #include "ui/aura/env.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/aura/window_targeter.h"
@@ -52,6 +53,10 @@ namespace {
 // window. If unset, no surface is associated with window.
 DEFINE_UI_CLASS_PROPERTY_KEY(Surface*, kSurfaceKey, nullptr);
 
+// A property key to store whether the surface should only consume
+// stylus input events.
+DEFINE_UI_CLASS_PROPERTY_KEY(bool, kStylusOnlyKey, false);
+
 // Helper function that returns an iterator to the first entry in |list|
 // with |key|.
 template <typename T, typename U>
@@ -634,6 +639,14 @@ void Surface::CheckIfSurfaceHierarchyNeedsCommitToNewSurfaces() {
     SetSurfaceHierarchyNeedsCommitToNewSurfaces();
 }
 
+bool Surface::IsStylusOnly() {
+  return window_->GetProperty(kStylusOnlyKey);
+}
+
+void Surface::SetStylusOnly() {
+  window_->SetProperty(kStylusOnlyKey, true);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // ui::ContextFactoryObserver overrides: