Feed ScrollableArea::showOverlayScrollbars into ScrollbarAnimationController.

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 <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 62 matching lines @@
       draw_blend_mode_(SkBlendMode::kSrcOver),
       transform_tree_index_(TransformTree::kInvalidNodeId),
       effect_tree_index_(EffectTree::kInvalidNodeId),
       clip_tree_index_(ClipTree::kInvalidNodeId),
       scroll_tree_index_(ScrollTree::kInvalidNodeId),
       current_draw_mode_(DRAW_MODE_NONE),
       mutable_properties_(MutableProperty::kNone),
       debug_info_(nullptr),
       has_will_change_transform_hint_(false),
       needs_push_properties_(false),
-      scrollbars_hidden_(false) {
+      scrollbars_hidden_(false),
+      needs_show_scrollbars_(false) {
   DCHECK_GT(layer_id_, 0);
 
   DCHECK(layer_tree_impl_);
   layer_tree_impl_->RegisterLayer(this);
   layer_tree_impl_->AddToElementMap(this);
 
   SetNeedsPushProperties();
 }
 
 LayerImpl::~LayerImpl() {
@@ skipping 237 matching lines @@
   layer->background_color_ = background_color_;
   layer->safe_opaque_background_color_ = safe_opaque_background_color_;
   layer->draw_blend_mode_ = draw_blend_mode_;
   layer->position_ = position_;
   layer->transform_tree_index_ = transform_tree_index_;
   layer->effect_tree_index_ = effect_tree_index_;
   layer->clip_tree_index_ = clip_tree_index_;
   layer->scroll_tree_index_ = scroll_tree_index_;
   layer->has_will_change_transform_hint_ = has_will_change_transform_hint_;
   layer->scrollbars_hidden_ = scrollbars_hidden_;
+  layer->needs_show_scrollbars_ = needs_show_scrollbars_;
 
   if (layer_property_changed_) {
     layer->layer_tree_impl()->set_needs_update_draw_properties();
     layer->layer_property_changed_ = true;
   }
 
   layer->SetBounds(bounds_);
   layer->SetScrollClipLayer(scroll_clip_layer_id_);
   layer->SetElementId(element_id_);
   layer->SetMutableProperties(mutable_properties_);
 
   // If the main thread commits multiple times before the impl thread actually
   // draws, then damage tracking will become incorrect if we simply clobber the
   // update_rect here. The LayerImpl's update_rect needs to accumulate (i.e.
   // union) any update changes that have occurred on the main thread.
   update_rect_.Union(layer->update_rect());
   layer->SetUpdateRect(update_rect_);
 
   if (owned_debug_info_)
     layer->SetDebugInfo(std::move(owned_debug_info_));
 
   // Reset any state that should be cleared for the next update.
+  needs_show_scrollbars_ = false;
   layer_property_changed_ = false;
   needs_push_properties_ = false;
   update_rect_ = gfx::Rect();
   layer_tree_impl()->RemoveLayerShouldPushProperties(this);
 }
 
 bool LayerImpl::IsAffectedByPageScale() const {
   TransformTree& transform_tree = GetTransformTree();
   return transform_tree.Node(transform_tree_index())
       ->in_subtree_of_page_scale_layer;
@@ skipping 605 matching lines @@
 
 ScrollTree& LayerImpl::GetScrollTree() const {
   return GetPropertyTrees()->scroll_tree;
 }
 
 TransformTree& LayerImpl::GetTransformTree() const {
   return GetPropertyTrees()->transform_tree;
 }
 
 }  // namespace cc