mus: Let clients set the cursor of their window.

ui/views/mus/native_widget_mus.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/mus/native_widget_mus.h"
 
 #include "base/thread_task_runner_handle.h"
 #include "components/mus/public/cpp/property_type_converters.h"
 #include "components/mus/public/cpp/window.h"
 #include "components/mus/public/cpp/window_property.h"
@@ skipping 577 matching lines @@
     int operation,
     ui::DragDropTypes::DragEventSource source) {
   // NOTIMPLEMENTED();
 }
 
 void NativeWidgetMus::SchedulePaintInRect(const gfx::Rect& rect) {
   content_->SchedulePaintInRect(rect);
 }
 
 void NativeWidgetMus::SetCursor(gfx::NativeCursor cursor) {
-  // NOTIMPLEMENTED();
+  // TODO(erg): In aura, our incoming cursor is really two
+  // parts. cursor.native_type() is an integer for standard cursors and is all
+  // we support right now. If native_type() == kCursorCustom, than we should
+  // also send an image, but as the cursor code is currently written, the image
+  // is in a platform native format that's already uploaded to the window
+  // server.
+  window_tree_host_->platform_window()->SetCursorById(
+      mus::mojom::Cursor(cursor.native_type()));
 }
 
 bool NativeWidgetMus::IsMouseEventsEnabled() const {
   // NOTIMPLEMENTED();
   return true;
 }
 
 void NativeWidgetMus::ClearNativeFocus() {
   // NOTIMPLEMENTED();
 }
@@ skipping 172 matching lines @@
   } else {
     native_widget_delegate_->OnScrollEvent(event);
   }
 }
 
 void NativeWidgetMus::OnGestureEvent(ui::GestureEvent* event) {
   native_widget_delegate_->OnGestureEvent(event);
 }
 
 }  // namespace views