Remove WeakPtrFactory from LayerAnimationSequence

ui/compositor/layer_animation_sequence.h

Index: ui/compositor/layer_animation_sequence.h
diff --git a/ui/compositor/layer_animation_sequence.h b/ui/compositor/layer_animation_sequence.h
index 2a414f30309a09a7501870c5d884c73007c82859..379ff54a0208b5dc0b6fefa4e581ac8cd8ed17ed 100644
--- a/ui/compositor/layer_animation_sequence.h
+++ b/ui/compositor/layer_animation_sequence.h
@@ -197,8 +197,6 @@ class COMPOSITOR_EXPORT LayerAnimationSequence
   // Used to tag animation elements to obtain metrics of animation performance.
   AnimationMetricsReporter* animation_metrics_reporter_;
 
-  base::WeakPtrFactory<LayerAnimationSequence> weak_ptr_factory_;
-
   DISALLOW_COPY_AND_ASSIGN(LayerAnimationSequence);
 };