Attempt to fix the crash in blink Scroll Animator.

third_party/WebKit/Source/platform/animation/CompositorAnimationPlayer.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "platform/animation/CompositorAnimationPlayer.h"
 
 #include "cc/animation/animation_id_provider.h"
 #include "platform/animation/CompositorAnimation.h"
 #include "public/platform/WebCompositorAnimationDelegate.h"
 #include "public/platform/WebLayer.h"
@@ skipping 54 matching lines @@
 void CompositorAnimationPlayer::abortAnimation(int animationId)
 {
     m_animationPlayer->AbortAnimation(animationId);
 }
 
 void CompositorAnimationPlayer::NotifyAnimationStarted(
     base::TimeTicks monotonicTime,
     cc::Animation::TargetProperty targetProperty,
     int group)
 {
-    ASSERT(m_delegate);
-    m_delegate->notifyAnimationStarted((monotonicTime - base::TimeTicks()).InSecondsF(), group);
+    if (m_delegate)
+        m_delegate->notifyAnimationStarted((monotonicTime - base::TimeTicks()).InSecondsF(), group);
 }
 
 void CompositorAnimationPlayer::NotifyAnimationFinished(
     base::TimeTicks monotonicTime,
     cc::Animation::TargetProperty targetProperty,
     int group)
 {
-    ASSERT(m_delegate);
-    m_delegate->notifyAnimationFinished((monotonicTime - base::TimeTicks()).InSecondsF(), group);
+    if (m_delegate)
+        m_delegate->notifyAnimationFinished((monotonicTime - base::TimeTicks()).InSecondsF(), group);
 }
 
 void CompositorAnimationPlayer::NotifyAnimationAborted(
     base::TimeTicks monotonicTime,
     cc::Animation::TargetProperty targetProperty,
     int group)
 {
-    ASSERT(m_delegate);
-    m_delegate->notifyAnimationAborted((monotonicTime - base::TimeTicks()).InSecondsF(), group);
+    if (m_delegate)
+        m_delegate->notifyAnimationAborted((monotonicTime - base::TimeTicks()).InSecondsF(), group);
 }
 
 } // namespace blink