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

services/ui/ws/display.h

Index: services/ui/ws/display.h
diff --git a/services/ui/ws/display.h b/services/ui/ws/display.h
index 98acc83ec341dd3de82475c22aa026a4a87b5a57..28cee3f14779dcf163bb1f4c070389a507847932 100644
--- a/services/ui/ws/display.h
+++ b/services/ui/ws/display.h
@@ -149,7 +149,8 @@ class Display : public PlatformDisplayDelegate,
   // |display_root| being destroyed.
   void RemoveWindowManagerDisplayRoot(WindowManagerDisplayRoot* display_root);
 
-  void UpdateNativeCursor(const ui::CursorData& cursor);
+  // Sets the native cursor to |cursor|.
+  void SetNativeCursor(const ui::CursorData& curosor);
 
   // mojom::WindowTreeHost:
   void SetSize(const gfx::Size& size) override;
@@ -167,6 +168,8 @@ class Display : public PlatformDisplayDelegate,
   using WindowManagerDisplayRootMap =
       std::map<UserId, WindowManagerDisplayRoot*>;
 
+  class CursorState;
+
   // Inits the necessary state once the display is ready.
   void InitWindowManagerDisplayRoots();
 
@@ -218,9 +221,6 @@ class Display : public PlatformDisplayDelegate,
   // external window mode this will be invalid.
   display::Display display_;
 
-  // The last cursor set. Used to track whether we need to change the cursor.
-  ui::CursorData last_cursor_;
-
   ServerWindowTracker activation_parents_;
 
   cc::LocalSurfaceIdAllocator allocator_;