Update SetPaintToLayer to accept LayerType

ui/views/controls/scrollbar/cocoa_scroll_bar.mm

 // 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.
 
 #import "ui/views/controls/scrollbar/cocoa_scroll_bar.h"
 
 #import "base/mac/sdk_forward_declarations.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/effects/SkGradientShader.h"
 #include "ui/compositor/layer.h"
@@ skipping 77 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(CocoaScrollBarThumb);
 };
 
 CocoaScrollBarThumb::CocoaScrollBarThumb(CocoaScrollBar* scroll_bar)
     : BaseScrollBarThumb(scroll_bar) {
   DCHECK(scroll_bar);
 
   // This is necessary, otherwise the thumb will be rendered below the views if
   // those views paint to their own layers.
-  SetPaintToLayer(true);
+  SetPaintToLayer();
   layer()->SetFillsBoundsOpaquely(false);
 }
 
 CocoaScrollBarThumb::~CocoaScrollBarThumb() {}
 
 bool CocoaScrollBarThumb::IsStateHovered() const {
   return GetState() == CustomButton::STATE_HOVERED;
 }
 
 bool CocoaScrollBarThumb::IsStatePressed() const {
@@ skipping 61 matching lines @@
       thickness_animation_(this),
       last_contents_scroll_offset_(0),
       is_expanded_(false),
       did_start_dragging_(false) {
   SetThumb(new CocoaScrollBarThumb(this));
   bridge_.reset([[ViewsScrollbarBridge alloc] initWithDelegate:this]);
   scroller_style_ = [ViewsScrollbarBridge getPreferredScrollerStyle];
 
   thickness_animation_.SetSlideDuration(kExpandDurationMs);
 
-  SetPaintToLayer(true);
+  SetPaintToLayer();
   has_scrolltrack_ = scroller_style_ == NSScrollerStyleLegacy;
   layer()->SetOpacity(scroller_style_ == NSScrollerStyleOverlay ? 0.0f : 1.0f);
 }
 
 CocoaScrollBar::~CocoaScrollBar() {
   [bridge_ clearDelegate];
 }
 
 //////////////////////////////////////////////////////////////////
 // CocoaScrollBar, BaseScrollBar:
@@ skipping 345 matching lines @@
 CocoaScrollBarThumb* CocoaScrollBar::GetCocoaScrollBarThumb() const {
   return static_cast<CocoaScrollBarThumb*>(GetThumb());
 }
 
 // static
 base::Timer* BaseScrollBar::GetHideTimerForTest(BaseScrollBar* scroll_bar) {
   return &static_cast<CocoaScrollBar*>(scroll_bar)->hide_scrollbar_timer_;
 }
 
 }  // namespace views