exo: Implement support for zwp_stylus_v1 protocol

components/exo/pointer.h

Index: components/exo/pointer.h
diff --git a/components/exo/pointer.h b/components/exo/pointer.h
index 5723c1f20362b247369c5024e21295b7d1526b29..183ee9401e45052a34be03d3d35abecb42a36ca9 100644
--- a/components/exo/pointer.h
+++ b/components/exo/pointer.h
@@ -27,6 +27,7 @@ class Widget;
 
 namespace exo {
 class PointerDelegate;
+class PointerStylusDelegate;
 class Surface;
 
 // This class implements a client pointer that represents one or more input
@@ -46,6 +47,9 @@ class Pointer : public ui::EventHandler,
   // pointer location, in surface local coordinates.
   void SetCursor(Surface* surface, const gfx::Point& hotspot);
 
+  // Set delegate for stylus events.
+  void SetStylusDelegate(PointerStylusDelegate* delegate);
+
   // Overridden from ui::EventHandler:
   void OnMouseEvent(ui::MouseEvent* event) override;
   void OnScrollEvent(ui::ScrollEvent* event) override;
@@ -73,6 +77,9 @@ class Pointer : public ui::EventHandler,
   // The delegate instance that all events are dispatched to.
   PointerDelegate* const delegate_;
 
+  // The delegate instance that all stylus related events are dispatched to.
+  PointerStylusDelegate* stylus_delegate_ = nullptr;
+
   // The widget for the pointer cursor.
   std::unique_ptr<views::Widget> widget_;
 
@@ -91,6 +98,15 @@ class Pointer : public ui::EventHandler,
   // The position of the pointer surface relative to the pointer location.
   gfx::Point hotspot_;
 
+  // The current pointer type.
+  ui::EventPointerType pointer_type_;
+
+  // The current pointer tilt.
+  gfx::Vector2dF tilt_;
+
+  // The current pointer force.
+  float force_;
+
   DISALLOW_COPY_AND_ASSIGN(Pointer);
 };