Valgrind is not a fan of uninitialized Src pixels.

bench/BitmapScaleBench.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 "Benchmark.h"
 #include "SkBlurMask.h"
 #include "SkCanvas.h"
@@ skipping 106 matching lines @@
 
 class PixmapScalerBench: public Benchmark {
     SkBitmapScaler::ResizeMethod    fMethod;
     SkString                        fName;
     SkBitmap                        fSrc, fDst;
 
 public:
     PixmapScalerBench(SkBitmapScaler::ResizeMethod method, const char suffix[]) : fMethod(method) {
         fName.printf("pixmapscaler_%s", suffix);
     }
-    
+
 protected:
     const char* onGetName() override {
         return fName.c_str();
     }
-    
+
     SkIPoint onGetSize() override { return{ 100, 100 }; }
 
     bool isSuitableFor(Backend backend) override {
         return backend == kNonRendering_Backend;
     }
 
     void onDelayedSetup() override {
         fSrc.allocN32Pixels(640, 480);
+        fSrc.eraseColor(SK_ColorWHITE);
         fDst.allocN32Pixels(300, 250);
     }
-    
+
     void onDraw(int loops, SkCanvas*) override {
         SkPixmap src, dst;
         fSrc.peekPixels(&src);
         fDst.peekPixels(&dst);
         for (int i = 0; i < loops * 16; i++) {
             SkBitmapScaler::Resize(dst, src, fMethod);
         }
     }
 
 private:
     typedef Benchmark INHERITED;
 };
 DEF_BENCH( return new PixmapScalerBench(SkBitmapScaler::RESIZE_LANCZOS3, "lanczos");  )
 DEF_BENCH( return new PixmapScalerBench(SkBitmapScaler::RESIZE_MITCHELL, "mitchell"); )
 DEF_BENCH( return new PixmapScalerBench(SkBitmapScaler::RESIZE_HAMMING,  "hamming");  )
 DEF_BENCH( return new PixmapScalerBench(SkBitmapScaler::RESIZE_TRIANGLE, "triangle"); )
 DEF_BENCH( return new PixmapScalerBench(SkBitmapScaler::RESIZE_BOX,      "box");      )