Remove uses of SkImageDecoder from samplecode

samplecode/SampleShaders.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
+#include "DecodeFile.h"
 #include "SampleCode.h"
 #include "SkView.h"
 #include "SkCanvas.h"
 #include "SkGradientShader.h"
 #include "SkGraphics.h"
-#include "SkImageDecoder.h"
 #include "SkPath.h"
 #include "SkRegion.h"
 #include "SkShader.h"
 #include "SkUtils.h"
 #include "SkXfermode.h"
 #include "SkColorPriv.h"
 #include "SkColorFilter.h"
 #include "SkTime.h"
 #include "SkTypeface.h"
 
@@ skipping 14 matching lines @@
 
     return SkShader::MakeComposeShader(std::move(shaderB), std::move(shaderA), mode);
 }
 
 class ShaderView : public SampleView {
 public:
     sk_sp<SkShader> fShader;
     SkBitmap        fBitmap;
 
     ShaderView() {
-        SkImageDecoder::DecodeFile("/skimages/logo.gif", &fBitmap);
+        decode_file("/skimages/logo.gif", &fBitmap);
 
         SkPoint pts[2];
         SkColor colors[2];
 
         pts[0].set(0, 0);
         pts[1].set(SkIntToScalar(100), 0);
         colors[0] = SK_ColorRED;
         colors[1] = SK_ColorBLUE;
         auto shaderA = SkGradientShader::MakeLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
 
@@ skipping 55 matching lines @@
     }
 
 private:
     typedef SampleView INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static SkView* MyFactory() { return new ShaderView; }
 static SkViewRegister reg(MyFactory);