ozone/wayland: Fix hiding cursor when playing media in fullscreen.

When using Chromium on Wayland, the cursor doesn't become invisible
whenever user enters fullscreen mode while watching any videos
(Eg. Youtube).

This patch fixes that feature.

Bug: 895743
Change-Id: Ic66c5342f63c374586855691ba395f33d4a49446
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2060431Reviewed-by: Maksim Sisov <msisov@igalia.com>
Commit-Queue: Maksim Sisov <msisov@igalia.com>
Cr-Commit-Position: refs/heads/master@{#744560}

ui/ozone/platform/wayland/host/wayland_cursor.cc

@@ -35,6 +35,8 @@ void WaylandCursor::Init(wl_pointer* pointer, WaylandConnection* connection) {
   shm_ = connection->shm();
   pointer_surface_.reset(
       wl_compositor_create_surface(connection->compositor()));
+
+  connection_ = connection;
 }
 
 void WaylandCursor::UpdateBitmap(const std::vector<SkBitmap>& cursor_image,
@@ -79,6 +81,11 @@ void WaylandCursor::UpdateBitmap(const std::vector<SkBitmap>& cursor_image,
 void WaylandCursor::HideCursor(uint32_t serial) {
   DCHECK(input_pointer_);
   wl_pointer_set_cursor(input_pointer_, serial, nullptr, 0, 0);
+
+  wl_surface_attach(pointer_surface_.get(), nullptr, 0, 0);
+  wl_surface_commit(pointer_surface_.get());
+
+  connection_->ScheduleFlush();
 }
 
 }  // namespace ui

ui/ozone/platform/wayland/host/wayland_cursor.h

@@ -57,6 +57,7 @@ class WaylandCursor {
 
   WaylandShm* shm_ = nullptr;            // Owned by WaylandConnection.
   wl_pointer* input_pointer_ = nullptr;  // Owned by WaylandPointer.
+  WaylandConnection* connection_ = nullptr;
 
   // Holds the buffers and their memory until the compositor releases them.
   base::flat_map<wl_buffer*, WaylandShmBuffer> buffers_;