Revert of Ensure that the focus ring in the bookmarks bar does not paint outside the parent view.

ui/views/controls/scroll_view.cc

Index: ui/views/controls/scroll_view.cc
diff --git a/ui/views/controls/scroll_view.cc b/ui/views/controls/scroll_view.cc
index c28b51349a29256aaea3138651c7fd2114859ae9..74cefcc61f7e9dd75aea8fc1593af824d7066290 100644
--- a/ui/views/controls/scroll_view.cc
+++ b/ui/views/controls/scroll_view.cc
@@ -61,16 +61,13 @@
 }
 
 // Make sure the content is not scrolled out of bounds
-void ConstrainScrollToBounds(View* viewport,
-                             View* view,
-                             bool scroll_with_layers_enabled) {
+void ConstrainScrollToBounds(View* viewport, View* view) {
   if (!view)
     return;
 
   // Note that even when ScrollView::ScrollsWithLayers() is true, the header row
   // scrolls by repainting.
-  const bool scrolls_with_layers =
-      scroll_with_layers_enabled && viewport->layer() != nullptr;
+  const bool scrolls_with_layers = viewport->layer() != nullptr;
   if (scrolls_with_layers) {
     DCHECK(view->layer());
     DCHECK_EQ(0, view->x());
@@ -155,9 +152,7 @@
       min_height_(-1),
       max_height_(-1),
       background_color_(SK_ColorTRANSPARENT),
-      hide_horizontal_scrollbar_(false),
-      scroll_with_layers_enabled_(
-          base::FeatureList::IsEnabled(kToolkitViewsScrollWithLayers)) {
+      hide_horizontal_scrollbar_(false) {
   set_notify_enter_exit_on_child(true);
 
   AddChildView(contents_viewport_);
@@ -171,9 +166,8 @@
   vert_sb_->set_controller(this);
   corner_view_->SetVisible(false);
 
-  if (!scroll_with_layers_enabled_)
-    return;
-
+  if (!base::FeatureList::IsEnabled(kToolkitViewsScrollWithLayers))
+    return;
   EnableViewPortLayer();
 }
 
@@ -456,10 +450,8 @@
   if (header_)
     header_->Layout();
 
-  ConstrainScrollToBounds(header_viewport_, header_,
-                          scroll_with_layers_enabled_);
-  ConstrainScrollToBounds(contents_viewport_, contents_,
-                          scroll_with_layers_enabled_);
+  ConstrainScrollToBounds(header_viewport_, header_);
+  ConstrainScrollToBounds(contents_viewport_, contents_);
   SchedulePaint();
   UpdateScrollBarPositions();
 }
@@ -533,16 +525,6 @@
 
 void ScrollView::OnNativeThemeChanged(const ui::NativeTheme* theme) {
   UpdateBorder();
-}
-
-void ScrollView::ViewHierarchyChanged(
-    const ViewHierarchyChangedDetails& details) {
-  if (details.is_add && !viewport_layer_enabled_ && Contains(details.parent))
-    EnableLayeringRecursivelyForChild(details.child);
-}
-
-void ScrollView::OnChildLayerChanged(View* child) {
-  EnableViewPortLayer();
 }
 
 void ScrollView::ScrollToPosition(ScrollBar* source, int position) {
@@ -735,18 +717,12 @@
 }
 
 bool ScrollView::ScrollsWithLayers() const {
-  if (!scroll_with_layers_enabled_)
-    return false;
   // Just check for the presence of a layer since it's cheaper than querying the
   // Feature flag each time.
   return contents_viewport_->layer() != nullptr;
 }
 
 void ScrollView::EnableViewPortLayer() {
-  if (viewport_layer_enabled_)
-    return;
-
-  viewport_layer_enabled_ = true;
   background_color_ = SK_ColorWHITE;
   contents_viewport_->set_background(
       Background::CreateSolidBackground(background_color_));
@@ -785,22 +761,6 @@
           draw_focus_indicator_
               ? ui::NativeTheme::kColorId_FocusedBorderColor
               : ui::NativeTheme::kColorId_UnfocusedBorderColor)));
-}
-
-bool ScrollView::EnableLayeringRecursivelyForChild(View* view) {
-  if (viewport_layer_enabled_ || scroll_with_layers_enabled_)
-    return true;
-
-  if (view->layer()) {
-    EnableViewPortLayer();
-    return true;
-  }
-
-  for (int i = 0; i < view->child_count(); ++i) {
-    if (EnableLayeringRecursivelyForChild(view->child_at(i)))
-      return true;
-  }
-  return false;
 }
 
 // VariableRowHeightScrollHelper ----------------------------------------------