Fix Picture-in-Picture window close icon.

This make sures the close icon in the Picture-in-Picture window is
centered properly.

Screenshot: https://imgur.com/a/3n6fNDW

Bug: 836389
Change-Id: Id3418ad003440ab60c28ba748096237b853d2c61
Reviewed-on: https://chromium-review.googlesource.com/1109937Reviewed-by: apacible <apacible@chromium.org>
Commit-Queue: François Beaufort <beaufort.francois@gmail.com>
Cr-Commit-Position: refs/heads/master@{#569572}

chrome/browser/ui/views/overlay/overlay_window_views.cc

@@ -309,7 +309,7 @@ void OverlayWindowViews::UpdateCloseControlsSize() {
   close_controls_view_->SetImage(
       views::Button::STATE_NORMAL,
       gfx::CreateVectorIcon(views::kIcCloseIcon,
-                            close_button_size_.width() * 2 / 3,
+                            std::round(close_button_size_.width() * 2.0 / 3.0),
                             kControlIconColor));
   const gfx::ImageSkia close_background =
       gfx::CreateVectorIcon(kPictureInPictureControlBackgroundIcon,