mus: Change PointerWatcher to observe all pointer events, with moves optional.

content/renderer/mus/compositor_mus_connection.cc

Index: content/renderer/mus/compositor_mus_connection.cc
diff --git a/content/renderer/mus/compositor_mus_connection.cc b/content/renderer/mus/compositor_mus_connection.cc
index a814c55906e2dd70ad906256d5b713585af6fbce..101c3a3a279dd754510ce58b0c3e0afd8ae81731 100644
--- a/content/renderer/mus/compositor_mus_connection.cc
+++ b/content/renderer/mus/compositor_mus_connection.cc
@@ -113,9 +113,10 @@ void CompositorMusConnection::OnEmbed(ui::Window* root) {
   }
 }
 
-void CompositorMusConnection::OnEventObserved(const ui::Event& event,
-                                              ui::Window* target) {
-  // Compositor does not use SetEventObserver().
+void CompositorMusConnection::OnPointerEventObserved(
+    const ui::PointerEvent& event,
+    ui::Window* target) {
+  // Compositor does not use StartPointerWatcher().
 }
 
 void CompositorMusConnection::OnWindowInputEvent(