Add {Lock,Unlock,Show,Hide}Cursor() to the window manager mojom.

services/ui/ws/window_manager_state.h

Index: services/ui/ws/window_manager_state.h
diff --git a/services/ui/ws/window_manager_state.h b/services/ui/ws/window_manager_state.h
index 502e535e035455303fdb815ec91f248961e1d64a..ce897244a81ee49e82e48e4f17faf0a33184868e 100644
--- a/services/ui/ws/window_manager_state.h
+++ b/services/ui/ws/window_manager_state.h
@@ -16,6 +16,7 @@
 #include "base/memory/weak_ptr.h"
 #include "base/timer/timer.h"
 #include "services/ui/public/interfaces/display_manager.mojom.h"
+#include "services/ui/ws/cursor_state.h"
 #include "services/ui/ws/event_dispatcher.h"
 #include "services/ui/ws/event_dispatcher_delegate.h"
 #include "services/ui/ws/server_window_observer.h"
@@ -90,6 +91,8 @@ class WindowManagerState : public EventDispatcherDelegate,
   // not be exposed.
   EventDispatcher* event_dispatcher() { return &event_dispatcher_; }
 
+  CursorState& cursor_state() { return cursor_state_; }
+
   // Returns true if this is the WindowManager of the active user.
   bool IsActive() const;
 
@@ -295,6 +298,9 @@ class WindowManagerState : public EventDispatcherDelegate,
   // destroyed.
   WindowManagerDisplayRoots orphaned_window_manager_display_roots_;
 
+  // All state regarding what the current cursor is.
+  CursorState cursor_state_;
+
   DISALLOW_COPY_AND_ASSIGN(WindowManagerState);
 };