[gtk/matthiasc/for-master] (12 commits) ...Quiet a compiler warning

[Matthias Clasen <matthiasc src gnome org>]

Summary of changes:

  682068f... gdk/x11: Serialize gtype content formats before sending Xdn (*)
  fe36c24... gdk/x11: Ensure to sync type list after sending XdndEnter (*)
  5aad3d7... gdk/x11: Ensure to hide DnD surface after failed operation (*)
  4716c9a... gdkdrag/x11: Drop timestamp argument from gdk_drag_do_leave (*)
  357e215... gdkdrag/x11: Issue XdndLeave on cancellation (*)
  975f652... Merge branch 'wip/carlosg/x11-dnd' into 'master' (*)
  fcceac6... css: Track hover state changes separately (*)
  64848ae... css: Track disabled state separately (*)
  2426b9e... css: Track backdrop state separately (*)
  192a24f... css: Track selected state separately (*)
  5ac24db... Merge branch 'matthiasc/css-split-states' into 'master' (*)
  fb2cc9a... Quiet a compiler warning

(*) This commit already existed in another branch; no separate mail sent