Convert GrClip to an abstract base class

src/gpu/GrBlurUtils.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 "GrBlurUtils.h"
 #include "GrDrawContext.h"
 #include "GrCaps.h"
@@ skipping 107 matching lines @@
         return nullptr;
     }
 
     drawContext->clear(nullptr, 0x0, true);
 
     GrPaint tempPaint;
     tempPaint.setAntiAlias(doAA);
     tempPaint.setCoverageSetOpXPFactory(SkRegion::kReplace_Op);
 
     // setup new clip
-    const SkRect clipRect = SkRect::MakeIWH(maskRect.width(), maskRect.height());
-    GrClip clip(clipRect);
+    const SkIRect clipRect = SkIRect::MakeWH(maskRect.width(), maskRect.height());
+    GrFixedClip clip(clipRect);
 
     // Draw the mask into maskTexture with the path's integerized top-left at
     // the origin using tempPaint.
     SkMatrix translate;
     translate.setTranslate(-SkIntToScalar(maskRect.fLeft), -SkIntToScalar(maskRect.fTop));
     drawContext->drawPath(clip, tempPaint, translate, devPath, GrStyle(fillOrHairline));
     return drawContext->asTexture();;
 }
 
 static void draw_path_with_mask_filter(GrContext* context,
@@ skipping 152 matching lines @@
     }
 
     if (paint.getMaskFilter()) {
         draw_path_with_mask_filter(context, drawContext, clip, &grPaint, viewMatrix,
                                    paint.getMaskFilter(), style,
                                    path, pathIsMutable);
     } else {
         drawContext->drawPath(clip, grPaint, viewMatrix, *path, style);
     }
 }