Attempt 2 at Fixes crash introduced @ 153047 (you can hit crash by maximizing a

ui/compositor/layer_animator.cc

Index: ui/compositor/layer_animator.cc
diff --git a/ui/compositor/layer_animator.cc b/ui/compositor/layer_animator.cc
index 5fc289b42c79868d2d8f2a161b1db0595eb381be..9213995d417bdf06da2cbb88c07c97d7cd251468 100644
--- a/ui/compositor/layer_animator.cc
+++ b/ui/compositor/layer_animator.cc
@@ -43,13 +43,16 @@ LayerAnimator::LayerAnimator(base::TimeDelta transition_duration)
       transition_duration_(transition_duration),
       tween_type_(Tween::LINEAR),
       is_started_(false),
-      disable_timer_for_test_(false) {
+      disable_timer_for_test_(false),
+      destroyed_(NULL) {
 }
 
 LayerAnimator::~LayerAnimator() {
   for (size_t i = 0; i < running_animations_.size(); ++i)
     running_animations_[i].sequence->OnAnimatorDestroyed();
   ClearAnimations();
+  if (destroyed_)
+    *destroyed_ = true;
 }
 
 // static
@@ -235,13 +238,16 @@ void LayerAnimator::StopAnimatingProperty(
     RunningAnimation* running = GetRunningAnimation(property);
     if (!running)
       break;
-    FinishAnimation(running->sequence);
+    if (FinishAnimation(running->sequence) == DESTROYED)
+      return;
   }
 }
 
 void LayerAnimator::StopAnimating() {
-  while (is_animating())
-    FinishAnimation(running_animations_[0].sequence);
+  while (is_animating()) {
+    if (FinishAnimation(running_animations_[0].sequence) == DESTROYED)
+      return;
+  }
 }
 
 void LayerAnimator::AddObserver(LayerAnimationObserver* observer) {
@@ -293,10 +299,12 @@ void LayerAnimator::Step(base::TimeTicks now) {
     base::TimeDelta delta = now - running_animations_copy[i].start_time;
     if (delta >= running_animations_copy[i].sequence->duration() &&
         !running_animations_copy[i].sequence->is_cyclic()) {
-      FinishAnimation(running_animations_copy[i].sequence);
+      if (FinishAnimation(running_animations_copy[i].sequence) == DESTROYED)
+        return;
       needs_redraw = true;
-    } else if (ProgressAnimation(running_animations_copy[i].sequence, delta))
+    } else if (ProgressAnimation(running_animations_copy[i].sequence, delta)) {
       needs_redraw = true;
+    }
   }
 
   if (needs_redraw && delegate())
@@ -356,11 +364,20 @@ LayerAnimationSequence* LayerAnimator::RemoveAnimation(
   return to_return.release();
 }
 
-void LayerAnimator::FinishAnimation(LayerAnimationSequence* sequence) {
+LayerAnimator::DestroyedType LayerAnimator::FinishAnimation(
+    LayerAnimationSequence* sequence) {
   scoped_ptr<LayerAnimationSequence> removed(RemoveAnimation(sequence));
-  sequence->Progress(sequence->duration(), delegate());
+  {
+    bool destroyed = false;
+    destroyed_ = &destroyed;
+    sequence->Progress(sequence->duration(), delegate());
+    if (destroyed)
+      return DESTROYED;
+    destroyed_ = NULL;
+  }
   ProcessQueue();
   UpdateAnimationState();
+  return NOT_DESTROYED;
 }
 
 void LayerAnimator::FinishAnyAnimationWithZeroDuration() {