Add clone to Stage. Rename place to mix and PolymorphicUnion to Stage. Cleanup.

gm/SkLinearBitmapPipelineGM.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 "SkBlitter.h"
 #include "SkCanvas.h"
@@ skipping 41 matching lines @@
     SkBitmap bmdst;
     bmdst.allocN32Pixels(ir.width(), ir.height());
     bmdst.eraseColor(0xFFFFFFFF);
     SkPixmap pmdst;
     bmdst.peekPixels(&pmdst);
 
     SkImageInfo info = SkImageInfo::MakeN32Premul(ir.width(), ir.height(), kLinear_SkColorProfileType);
 
     sk_sp<SkImage> image(SkImage::MakeRasterCopy(SkPixmap(info, pmsrc.addr32(), pmsrc.rowBytes())));
     SkPaint paint;
-    int32_t storage[300];
+    int32_t storage[400];
 
     sk_sp<SkShader> shader = image->makeShader(SkShader::kRepeat_TileMode,
                                                SkShader::kRepeat_TileMode);
 
     if (useBilerp) {
         paint.setFilterQuality(SkFilterQuality::kLow_SkFilterQuality);
     } else {
         paint.setFilterQuality(SkFilterQuality::kNone_SkFilterQuality);
     }
     paint.setShader(std::move(shader));
@@ skipping 122 matching lines @@
             }
             canvas->restore();
             canvas->translate(0, H + 20);
         }
         canvas->restore();
         canvas->translate(0, (H + 20) * SK_ARRAY_COUNT(mats));
         if (useBilerp) break;
         useBilerp = true;
     }
 }