Fix leak of effect in SkXfermodeImageFilter::filterImageGPU()

src/effects/SkXfermodeImageFilter.cpp

 /*
  * Copyright 2013 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkXfermodeImageFilter.h"
 #include "SkCanvas.h"
 #include "SkColorPriv.h"
@@ skipping 84 matching lines @@
     if (!SkXfermode::AsNewEffectOrCoeff(fMode, context, &xferEffect, &sm, &dm, backgroundTex)) {
         return false;
     }
 
     GrPaint paint;
     SkRect srcRect;
     src.getBounds(&srcRect);
     if (NULL != xferEffect) {
         paint.colorStage(0)->setEffect(
             GrSimpleTextureEffect::Create(foregroundTex, GrEffect::MakeDivByTextureWHMatrix(foregroundTex)))->unref();
-        paint.colorStage(1)->setEffect(xferEffect);
+        paint.colorStage(1)->setEffect(xferEffect)->unref();
         context->drawRect(paint, srcRect);
     } else {
         paint.colorStage(0)->setEffect(
             GrSimpleTextureEffect::Create(backgroundTex, GrEffect::MakeDivByTextureWHMatrix(backgroundTex)))->unref();
         context->drawRect(paint, srcRect);
         paint.setBlendFunc(sk_blend_to_grblend(sm), sk_blend_to_grblend(dm));
         paint.colorStage(0)->setEffect(
             GrSimpleTextureEffect::Create(foregroundTex, GrEffect::MakeDivByTextureWHMatrix(foregroundTex)))->unref();
         context->drawRect(paint, srcRect);
     }
     return SkImageFilterUtils::WrapTexture(dst, src.width(), src.height(), result);
 }
 
 #endif