Fix a crash in dtor of CallbackAnimationObserver

ui/keyboard/keyboard_controller.cc

Index: ui/keyboard/keyboard_controller.cc
diff --git a/ui/keyboard/keyboard_controller.cc b/ui/keyboard/keyboard_controller.cc
index 5aa44bbbaf599bf7c431ec55456e8e7277092d80..f410b4c97373de94e8d3be972ae5733c95e76018 100644
--- a/ui/keyboard/keyboard_controller.cc
+++ b/ui/keyboard/keyboard_controller.cc
@@ -124,6 +124,7 @@ class CallbackAnimationObserver : public ui::LayerAnimationObserver {
   void OnLayerAnimationEnded(ui::LayerAnimationSequence* seq) override;
   void OnLayerAnimationAborted(ui::LayerAnimationSequence* seq) override;
   void OnLayerAnimationScheduled(ui::LayerAnimationSequence* seq) override {}
+  bool RequiresNotificationWhenAnimatorDestroyed() const override;
 
   ui::LayerAnimator* animator_;

[sadrul, 2015/04/23 23:07:59]

Should this be a scoped_refptr<> instead?

[bshe, 2015/04/24 14:24:37]

Great suggestion! Done.

   base::Callback<void(void)> callback_;
@@ -137,7 +138,8 @@ CallbackAnimationObserver::CallbackAnimationObserver(
 }
 
 CallbackAnimationObserver::~CallbackAnimationObserver() {
-  animator_->RemoveObserver(this);
+  if (animator_)
+    animator_->RemoveObserver(this);
 }
 
 void CallbackAnimationObserver::OnLayerAnimationEnded(
@@ -146,11 +148,18 @@ void CallbackAnimationObserver::OnLayerAnimationEnded(
     return;
   animator_->RemoveObserver(this);
   callback_.Run();
+  animator_ = NULL;
 }
 
 void CallbackAnimationObserver::OnLayerAnimationAborted(
     ui::LayerAnimationSequence* seq) {
   animator_->RemoveObserver(this);
+  animator_ = NULL;
+}
+
+bool CallbackAnimationObserver::RequiresNotificationWhenAnimatorDestroyed()
+    const {
+  return true;
 }
 
 class WindowBoundsChangeObserver : public aura::WindowObserver {