Make sure SkDrawLooper objects can only be allocated on the heap.

gm/megalooper.cpp

 /*
  * Copyright 2013 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 "SkBlurMask.h"
 #include "SkBlurMaskFilter.h"
@@ skipping 145 matching lines @@
                 // looper will undo this translation)
                 rect.offset(SkIntToScalar(kOffsetToOutsideClip), 0);
 
                 canvas->drawRect(rect, loopPaint);
             canvas->restore();
         }
     }
 
     // Create a 1-tier drawlooper
     SkLayerDrawLooper* create1Looper(SkScalar xOff, SkScalar yOff, SkColor color) {
-        SkLayerDrawLooper* looper = new SkLayerDrawLooper;
+        SkLayerDrawLooper::Builder looperBuilder;
         SkLayerDrawLooper::LayerInfo info;
 
         info.fPaintBits = SkLayerDrawLooper::kColorFilter_Bit |
                           SkLayerDrawLooper::kMaskFilter_Bit;
         info.fColorMode = SkXfermode::kSrc_Mode;
         info.fOffset.set(xOff, yOff);
         info.fPostTranslate = false;
 
-        SkPaint* paint = looper->addLayer(info);
+        SkPaint* paint = looperBuilder.addLayer(info);
 
         paint->setMaskFilter(this->createBlur())->unref();
 
         SkColorFilter* cf = SkColorFilter::CreateModeFilter(color, SkXfermode::kSrcIn_Mode);
         paint->setColorFilter(cf)->unref();
 
-        return looper;
+        return looperBuilder.detachLooper();
     }
 
     void draw1x4(SkCanvas* canvas, SkScalar x, SkScalar y) {
         SkRect rect = { -kHalfSquareSize, -kHalfSquareSize, kHalfSquareSize, kHalfSquareSize };
         rect.offset(x, y);
 
         SkRect outerClip = {
             -kHalfOuterClipSize-kHalfSquareSize, -kHalfOuterClipSize-kHalfSquareSize,
              kHalfOuterClipSize+kHalfSquareSize,  kHalfOuterClipSize+kHalfSquareSize
         };
         outerClip.offset(x, y);
 
         SkPaint paint;
         paint.setAntiAlias(true);
         paint.setLooper(create4Looper(-kOffsetToOutsideClip-kHalfSquareSize, 0))->unref();
 
         canvas->save();
             canvas->clipRect(outerClip, SkRegion::kIntersect_Op);
             canvas->clipRect(rect, SkRegion::kDifference_Op);
 
             rect.offset(SkIntToScalar(kOffsetToOutsideClip+kHalfSquareSize), 0);
             canvas->drawRect(rect, paint);
         canvas->restore();
     }
 
     // Create a 4-tier draw looper
     SkLayerDrawLooper* create4Looper(SkScalar xOff, SkScalar yOff) {
-        SkLayerDrawLooper* looper = new SkLayerDrawLooper;
+        SkLayerDrawLooper::Builder looperBuilder;
         SkLayerDrawLooper::LayerInfo info;
 
         info.fPaintBits = SkLayerDrawLooper::kColorFilter_Bit |
                           SkLayerDrawLooper::kMaskFilter_Bit;
         info.fColorMode = SkXfermode::kSrc_Mode;
         info.fPostTranslate = false;
 
         SkPaint* paint;
 
         for (int i = 3; i >= 0; --i) {
             info.fOffset.set(xOff+gBlurOffsets[i].fX, yOff+gBlurOffsets[i].fY);
-            paint = looper->addLayer(info);
+            paint = looperBuilder.addLayer(info);
 
             paint->setMaskFilter(this->createBlur())->unref();
 
             SkColorFilter* cf = SkColorFilter::CreateModeFilter(gColors[i], SkXfermode::kSrcIn_Mode);
             paint->setColorFilter(cf)->unref();
         }
 
-        return looper;
+        return looperBuilder.detachLooper();
     }
 
     typedef GM INHERITED;
 };
 
 const SkPoint MegaLooperGM::gBlurOffsets[4] = {
     {  kHalfSquareSize,  kHalfSquareSize },
     { -kHalfSquareSize,  kHalfSquareSize },
     {  kHalfSquareSize, -kHalfSquareSize },
     { -kHalfSquareSize, -kHalfSquareSize }
 };
 
 const SkColor MegaLooperGM::gColors[4] = {
     SK_ColorGREEN, SK_ColorYELLOW, SK_ColorBLUE, SK_ColorRED
 };
 
 DEF_GM( return new MegaLooperGM(MegaLooperGM::k0x0_Type); )
 DEF_GM( return new MegaLooperGM(MegaLooperGM::k4x1_Type); )
 DEF_GM( return new MegaLooperGM(MegaLooperGM::k1x4_Type); )