Don't use complex blend mode for shapes gm

gm/shapes.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 #include "SkRandom.h"
 #include "SkRRect.h"
@@ skipping 41 matching lines @@
 
         if (!antialias) {
             fName.append("_bw");
         }
     }
 
     SkString onShortName() override final { return fName; }
     SkISize onISize() override { return SkISize::Make(500, 500); }
 
     void onOnceBeforeDraw() override {
-        fPaint.setXfermodeMode(SkXfermode::kDarken_Mode);
         fPaint.setAntiAlias(fAntialias);
     }
 
     void onDraw(SkCanvas* canvas) override {
         canvas->clear(SK_ColorWHITE);
 
         canvas->save();
         canvas->translate(canvas->imageInfo().width() / 2.f, canvas->imageInfo().height() / 2.f);
         this->drawShapes(canvas);
         canvas->restore();
@@ skipping 81 matching lines @@
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 DEF_GM( return new SimpleShapesGM(true); )
 DEF_GM( return new SimpleShapesGM(false); )
 DEF_GM( return new InnerShapesGM(true); )
 DEF_GM( return new InnerShapesGM(false); )
 
 }