core: track active connection dependencies

Track a master active connection and emit wait/ready/fail when
it changes state.  This signal is intended for devices to
delay their activation until a master device is ready.

src/nm-activation-request.h

@@ -34,6 +34,15 @@
 #define NM_IS_ACT_REQUEST_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((obj), NM_TYPE_ACT_REQUEST))
 #define NM_ACT_REQUEST_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), NM_TYPE_ACT_REQUEST, NMActRequestClass))
 
+typedef enum {
+	NM_ACT_REQUEST_DEP_RESULT_UNKNOWN,
+	NM_ACT_REQUEST_DEP_RESULT_WAIT,
+	NM_ACT_REQUEST_DEP_RESULT_READY,
+	NM_ACT_REQUEST_DEP_RESULT_FAILED,
+} NMActRequestDependencyResult;
+
+#define NM_ACT_REQUEST_DEPENDENCY_RESULT "dependency-result"
+
 typedef struct {
 	GObject parent;
 } NMActRequest;
@@ -43,6 +52,8 @@ typedef struct {
 
 	/* Signals */
 	void (*properties_changed) (NMActRequest *req, GHashTable *properties);
+
+	void (*dependency_result) (NMActRequest *req, NMActRequestDependencyResult result);
 } NMActRequestClass;
 
 GType nm_act_request_get_type (void);
@@ -53,7 +64,7 @@ NMActRequest *nm_act_request_new          (NMConnection *connection,
                                            gulong user_uid,
                                            gboolean assumed,
                                            gpointer *device,  /* An NMDevice */
-                                           NMActiveConnection *master);
+                                           NMActiveConnection *dependency);
 
 NMConnection *nm_act_request_get_connection     (NMActRequest *req);
 
@@ -71,6 +82,8 @@ GObject *     nm_act_request_get_device (NMActRequest *req);
 
 gboolean      nm_act_request_get_assumed (NMActRequest *req);
 
+NMActRequestDependencyResult nm_act_request_get_dependency_result (NMActRequest *req);
+
 /* Secrets handling */
 
 typedef void (*NMActRequestSecretsFunc) (NMActRequest *req,