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..25865b34ea4113c0e8e5bc6c8214a1ea805e8e6b 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 this surface represents an annotation layer.
+  bool GetAnnotationLayer() const { return annotation_layer_; }

[reveman, 2017/05/23 16:41:06]

Can we add an ash window property for this instead of requiring browser code to
depend on exo?

[Vladislav Kaznacheev, 2017/05/23 23:48:56]

Done.

+
+  // Sets the "annotation layer" flag.
+  void SetAnnotationLayer(bool on) { annotation_layer_ = on; }

[reveman, 2017/05/23 16:41:06]

exo::Surface API should match the wayland interface as closely as possible to
avoid introducing unnecessary terms and concepts. ie. the name here should match
the request we add to the wayland interface for turning this on/off

[Vladislav Kaznacheev, 2017/05/23 23:48:55]

Done.

+
   // Overridden from ui::ContextFactoryObserver:
   void OnLostResources() override;
 
@@ -387,6 +393,9 @@ class Surface : public ui::ContextFactoryObserver,
   bool needs_begin_frame_ = false;
   cc::BeginFrameAck current_begin_frame_ack_;
 
+  // Whether this surface represents an annotation layer.
+  bool annotation_layer_ = false;
+
   DISALLOW_COPY_AND_ASSIGN(Surface);
 };