Update from https://crrev.com/308331

cc/layers/layer_impl.cc

 // Copyright 2012 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 "cc/layers/layer_impl.h"
 
 #include "base/debug/trace_event.h"
 #include "base/debug/trace_event_argument.h"
 #include "base/json/json_reader.h"
 #include "base/strings/stringprintf.h"
@@ skipping 1250 matching lines @@
 }
 
 void LayerImpl::SetScrollbarPosition(ScrollbarLayerImplBase* scrollbar_layer,
                                      LayerImpl* scrollbar_clip_layer,
                                      bool on_resize) const {
   DCHECK(scrollbar_layer);
   LayerImpl* page_scale_layer = layer_tree_impl()->page_scale_layer();
 
   DCHECK(this != page_scale_layer);
   DCHECK(scrollbar_clip_layer);
-  DCHECK(this != layer_tree_impl()->InnerViewportScrollLayer() ||
-         IsContainerForFixedPositionLayers());
   gfx::RectF clip_rect(gfx::PointF(),
                        scrollbar_clip_layer->BoundsForScrolling());
 
   // See comment in MaxScrollOffset() regarding the use of the content layer
   // bounds here.
   gfx::RectF scroll_rect(gfx::PointF(), BoundsForScrolling());
 
   if (scroll_rect.size().IsEmpty())
     return;
 
@@ skipping 307 matching lines @@
 
 void LayerImpl::NotifyAnimationFinished(
     base::TimeTicks monotonic_time,
     Animation::TargetProperty target_property,
     int group) {
   if (target_property == Animation::ScrollOffset)
     layer_tree_impl_->InputScrollAnimationFinished();
 }
 
 }  // namespace cc