[mutter] keybindings: Add "no-auto-grab" type

[Carlos Garnacho <carlosg src gnome org>]

commit 1c3d8defb5adeb84a0f58d571edc8fc8eb340dce
Author: Olivier Fourdan <ofourdan redhat com>
Date:   Mon Jul 15 17:24:35 2019 +0200

    keybindings: Add "no-auto-grab" type
    
    Some special modifiers (typically "Control_L" used for locate-pointer in
    mutter/gnome-shell or "Super_L" for overlay) must be handled separately
    from the rest of the key bindings.
    
    Add a new flag `META_KEY_BINDING_NO_AUTO_GRAB` so we can tell when
    dealing with that special keybinding which should not be grabbed
    automatically like the rest of the keybindings, and skip those when
    changing the grabs of all keybindings.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/685

 src/core/keybindings.c | 6 ++++++
 src/meta/prefs.h       | 2 ++
 2 files changed, 8 insertions(+)
---
diff --git a/src/core/keybindings.c b/src/core/keybindings.c
index e474b25c7..2526d04a3 100644
--- a/src/core/keybindings.c
+++ b/src/core/keybindings.c
@@ -1463,6 +1463,12 @@ change_keygrab_foreach (gpointer key,
   if (data->only_per_window != binding_is_per_window)
     return;
 
+  /* Ignore the key bindings marked as META_KEY_BINDING_NO_AUTO_GRAB,
+   * those are handled separately
+   */
+  if (binding->flags & META_KEY_BINDING_NO_AUTO_GRAB)
+    return;
+
   if (binding->resolved_combo.len == 0)
     return;
 
diff --git a/src/meta/prefs.h b/src/meta/prefs.h
index 9db540453..36ebc1fa1 100644
--- a/src/meta/prefs.h
+++ b/src/meta/prefs.h
@@ -436,6 +436,7 @@ typedef enum _MetaKeyBindingAction
  * @META_KEY_BINDING_BUILTIN: built-in
  * @META_KEY_BINDING_IS_REVERSED: is reversed
  * @META_KEY_BINDING_NON_MASKABLE: always active
+ * @META_KEY_BINDING_NO_AUTO_GRAB: not grabbed automatically
  */
 typedef enum
 {
@@ -445,6 +446,7 @@ typedef enum
   META_KEY_BINDING_IS_REVERSED  = 1 << 2,
   META_KEY_BINDING_NON_MASKABLE = 1 << 3,
   META_KEY_BINDING_IGNORE_AUTOREPEAT = 1 << 4,
+  META_KEY_BINDING_NO_AUTO_GRAB = 1 << 5,
 } MetaKeyBindingFlags;
 
 /**