Hide SkPixelXorXfermode from Chrome

gm/pixelxorxfermode.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 "Resources.h"
 
 #include "SkImageDecoder.h"
 #include "SkPixelXorXfermode.h"
 #include "SkStream.h"
 
+#if SK_INCLUDE_DEPRECATED_XFERMODES
+
 class PixelXorXfermodeGM : public skiagm::GM {
 public:
     PixelXorXfermodeGM() { }
 
 protected:
     SkString onShortName() override {
         return SkString("pixelxorxfermode");
     }
 
     SkISize onISize() override { return SkISize::Make(512, 512); }
@@ skipping 59 matching lines @@
 
 private:
     SkBitmap fBM;
 
     typedef GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 DEF_GM(return new PixelXorXfermodeGM;)
+
+#endif