Add an option on SkImageDecoder to skip writing 0s.

src/images/SkImageDecoder_libbmp.cpp

 
 /*
  * Copyright 2007 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 "bmpdecoderhelper.h"
@@ skipping 128 matching lines @@
     if (justBounds) {
         return true;
     }
 
     if (!this->allocPixelRef(bm, NULL)) {
         return false;
     }
 
     SkAutoLockPixels alp(*bm);
 
-    if (!sampler.begin(bm, SkScaledBitmapSampler::kRGB, getDitherImage())) {
+    if (!sampler.begin(bm, SkScaledBitmapSampler::kRGB, *this)) {
         return false;
     }
 
     const int srcRowBytes = width * 3;
     const int dstHeight = sampler.scaledHeight();
     const uint8_t* srcRow = callback.rgb();
 
     srcRow += sampler.srcY0() * srcRowBytes;
     for (int y = 0; y < dstHeight; y++) {
         sampler.next(srcRow);
         srcRow += sampler.srcDY() * srcRowBytes;
     }
     return true;
 }