Use sk_sp-based shader creation APIs

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 236 matching lines @@
   gfx::Rect track_rect = GetLocalBounds();
 
   SkPoint gradient_bounds[2];
   if (IsHorizontal()) {
     gradient_bounds[0].set(track_rect.x(), track_rect.y());
     gradient_bounds[1].set(track_rect.x(), track_rect.bottom());
   } else {
     gradient_bounds[0].set(track_rect.x(), track_rect.y());
     gradient_bounds[1].set(track_rect.right(), track_rect.y());
   }
-  skia::RefPtr<SkShader> shader = skia::AdoptRef(SkGradientShader::CreateLinear(
+  SkPaint gradient;
+  gradient.setShader(SkGradientShader::MakeLinear(
       gradient_bounds, kScrollerTrackGradientColors, nullptr,
       arraysize(kScrollerTrackGradientColors), SkShader::kClamp_TileMode));
-  SkPaint gradient;
-  gradient.setShader(shader.get());
   canvas->DrawRect(track_rect, gradient);
 
   // Draw the inner border: top if horizontal, left if vertical.
   SkPaint paint;
   paint.setColor(kScrollerTrackInnerBorderColor);
   gfx::Rect inner_border(track_rect);
   if (IsHorizontal())
     inner_border.set_height(kScrollerTrackBorderWidth);
   else
     inner_border.set_width(kScrollerTrackBorderWidth);
@@ skipping 207 matching lines @@
 void CocoaScrollBar::SetScrolltrackVisible(bool visible) {
   has_scrolltrack_ = visible;
   SchedulePaint();
 }
 
 CocoaScrollBarThumb* CocoaScrollBar::GetCocoaScrollBarThumb() const {
   return static_cast<CocoaScrollBarThumb*>(GetThumb());
 }
 
 }  // namespace views