use simpler gradient factories (in prep for removing SkUnitMapper param)

content/browser/web_contents/aura/shadow_layer_delegate.cc

 // Copyright (c) 2013 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 "content/browser/web_contents/aura/shadow_layer_delegate.h"
 
 #include "base/bind.h"
 #include "third_party/skia/include/effects/SkGradientShader.h"
 #include "ui/aura/window.h"
 #include "ui/compositor/layer.h"
@@ skipping 24 matching lines @@
 
 void ShadowLayerDelegate::OnPaintLayer(gfx::Canvas* canvas) {
   SkPoint points[2];
   const SkColor kShadowColors[2] = { kShadowLightColor, kShadowDarkColor };
 
   points[0].iset(0, 0);
   points[1].iset(kShadowThick, 0);
 
   skia::RefPtr<SkShader> shader = skia::AdoptRef(
       SkGradientShader::CreateLinear(points, kShadowColors, NULL,
-          arraysize(points), SkShader::kRepeat_TileMode, NULL));
+          arraysize(points), SkShader::kRepeat_TileMode));
 
   gfx::Rect paint_rect = gfx::Rect(0, 0, kShadowThick,
                                    layer_->bounds().height());
   SkPaint paint;
   paint.setShader(shader.get());
   canvas->sk_canvas()->drawRect(gfx::RectToSkRect(paint_rect), paint);
 }
 
 void ShadowLayerDelegate::OnDeviceScaleFactorChanged(float scale_factor) {
 }
 
 base::Closure ShadowLayerDelegate::PrepareForLayerBoundsChange() {
   return base::Bind(&base::DoNothing);
 }
 
 }  // namespace content