cc: Move SkShader construction to a single spot in PaintShader

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 "cc/paint/paint_shader.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/effects/SkGradientShader.h"
@@ skipping 240 matching lines @@
 
   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());
   }
   cc::PaintFlags gradient;
-  gradient.setShader(cc::WrapSkShader(SkGradientShader::MakeLinear(
+  gradient.setShader(cc::PaintShader::MakeLinearGradient(
       gradient_bounds, kScrollerTrackGradientColors, nullptr,
-      arraysize(kScrollerTrackGradientColors), SkShader::kClamp_TileMode)));
+      arraysize(kScrollerTrackGradientColors), SkShader::kClamp_TileMode));
   canvas->DrawRect(track_rect, gradient);
 
   // Draw the inner border: top if horizontal, left if vertical.
   cc::PaintFlags flags;
   flags.setColor(kScrollerTrackInnerBorderColor);
   gfx::Rect inner_border(track_rect);
   if (IsHorizontal())
     inner_border.set_height(kScrollerTrackBorderWidth);
   else
     inner_border.set_width(kScrollerTrackBorderWidth);
@@ skipping 263 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