After bug #695905 is fixed, I see this:

==29897== 24 bytes in 1 blocks are definitely lost in loss record 3,727 of 11,645
==29897==    at 0x4A0887C: malloc (vg_replace_malloc.c:270)
==29897==    by 0x7D8275E: g_malloc (gmem.c:159)
==29897==    by 0x7D9B005: g_slice_alloc (gslice.c:1003)
==29897==    by 0x7D9B045: g_slice_alloc0 (gslice.c:1029)
==29897==    by 0x452B21: save_data_new (ephy-session.c:716)
==29897==    by 0x4532E2: ephy_session_save (ephy-session.c:949)
==29897==    by 0x45236E: window_added_cb (ephy-session.c:464)
==29897==    by 0x7CE57EE: g_cclosure_marshal_VOID__OBJECT (gmarshal.c:1272)
==29897==    by 0x7CE0BEC: g_closure_invoke (gclosure.c:777)
==29897==    by 0x7CFE892: signal_emit_unlocked_R (gsignal.c:3584)
==29897==    by 0x7CFDADA: g_signal_emit_valist (gsignal.c:3328)
==29897==    by 0x7CFE022: g_signal_emit (gsignal.c:3384)
==29897==    by 0x743CE52: gtk_application_add_window (gtkapplication.c:836)
==29897==    by 0x77567F3: gtk_window_set_application (gtkwindow.c:2777)
==29897==    by 0x77531E1: gtk_window_set_property (gtkwindow.c:1286)
==29897==    by 0x7CE899D: object_set_property (gobject.c:1358)
==29897==    by 0x7CE9854: g_object_newv (gobject.c:1751)
==29897==    by 0x7CE9E76: g_object_new_valist (gobject.c:1836)
==29897==    by 0x7CE9111: g_object_new (gobject.c:1551)
==29897==    by 0x439B70: ephy_window_new_with_chrome (ephy-window.c:4126)