Minor code cleanup (left over from prior CL)

gm/imagefilterstransformed.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "sk_tool_utils.h"
 #include "SkBitmapSource.h"
 #include "SkBlurImageFilter.h"
@@ skipping 36 matching lines @@
         SkAutoTUnref<SkShader> shader(
             SkGradientShader::CreateRadial(SkPoint::Make(x, y), radius, colors, nullptr, 2,
                                            SkShader::kClamp_TileMode)
         );
         SkPaint paint;
         paint.setShader(shader);
         canvas.drawCircle(x, y, radius, paint);
     }
 
     void onOnceBeforeDraw() override {
-        fCheckerboard.allocN32Pixels(64, 64);
-        SkCanvas checkerboardCanvas(fCheckerboard);
-        sk_tool_utils::draw_checkerboard(&checkerboardCanvas, 0xFFA0A0A0, 0xFF404040, 8);
-
+        fCheckerboard = sk_tool_utils::create_checkerboard_bitmap(64, 64,
+                                                                  0xFFA0A0A0, 0xFF404040, 8);
         this->makeGradientCircle(64, 64);
     }
 
     void onDraw(SkCanvas* canvas) override {
         SkAutoTUnref<SkImageFilter> gradient(SkBitmapSource::Create(fGradientCircle));
         SkAutoTUnref<SkImageFilter> checkerboard(SkBitmapSource::Create(fCheckerboard));
         SkImageFilter* filters[] = {
             SkBlurImageFilter::Create(12, 0),
             SkDropShadowImageFilter::Create(0, 15, 8, 0, SK_ColorGREEN,
                 SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode),
@@ skipping 44 matching lines @@
     SkBitmap fCheckerboard;
     SkBitmap fGradientCircle;
     typedef GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 DEF_GM( return new ImageFiltersTransformedGM; )
 
 }