[gnome-builder/gnome-builder-3-24] egg: always use current monotonic time for animation start

[Christian Hergert <chergert src gnome org>]

commit 7cfe02ec920f0a90f4d2b71cd4dd58e6d70c9782
Author: Christian Hergert <chergert redhat com>
Date:   Sat Apr 15 19:25:09 2017 -0700

    egg: always use current monotonic time for animation start
    
    The time coming from the frame clock could be a bit outdated, so we want
    to ensure we get the current time for the animation start.
    
    This was causing some animations to complete in one frame if the clock was
    frozen when we started.

 contrib/egg/egg-animation.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/contrib/egg/egg-animation.c b/contrib/egg/egg-animation.c
index 295d086..8b9f7f7 100644
--- a/contrib/egg/egg-animation.c
+++ b/contrib/egg/egg-animation.c
@@ -613,9 +613,14 @@ egg_animation_start (EggAnimation *animation)
   g_object_ref_sink (animation);
   egg_animation_load_begin_values (animation);
 
+  /*
+   * We want the real current time instead of the GdkFrameClocks current time
+   * because if the clock was asleep, it could be innaccurate.
+   */
+  animation->begin_msec = g_get_monotonic_time () / 1000UL;
+
   if (animation->frame_clock)
     {
-      animation->begin_msec = gdk_frame_clock_get_frame_time (animation->frame_clock) / 1000UL;
       animation->tween_handler =
         g_signal_connect (animation->frame_clock,
                           "update",
@@ -630,7 +635,6 @@ egg_animation_start (EggAnimation *animation)
     }
   else
     {
-      animation->begin_msec = g_get_monotonic_time () / 1000UL;
       animation->tween_handler = egg_frame_source_add (FALLBACK_FRAME_RATE,
                                                        egg_animation_timeout_cb,
                                                        animation);