Convert GrClip to an abstract base class

src/gpu/GrYUVProvider.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 "GrContext.h"
 #include "GrDrawContext.h"
 #include "GrYUVProvider.h"
@@ skipping 129 matching lines @@
             paint.setDisableOutputConversionToSRGB(true);
         } else {
             paint.addColorFragmentProcessor(GrGammaEffect::Create(2.2f))->unref();
         }
     }
 
     paint.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
     const SkRect r = SkRect::MakeIWH(yuvInfo.fSizeInfo.fSizes[SkYUVSizeInfo::kY].fWidth,
             yuvInfo.fSizeInfo.fSizes[SkYUVSizeInfo::kY].fHeight);
 
-    drawContext->drawRect(GrClip::WideOpen(), paint, SkMatrix::I(), r);
+    drawContext->drawRect(GrNoClip(), paint, SkMatrix::I(), r);
 
     return drawContext->asTexture();
 }