Add subsetting to SkScanlineDecoder

src/codec/SkBmpStandardCodec.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBmpStandardCodec.h"
 #include "SkCodecPriv.h"
 #include "SkColorPriv.h"
@@ skipping 143 matching lines @@
         if (stream()->skip(fOffset - colorBytes) != fOffset - colorBytes) {
             SkCodecPrintf("Error: unable to skip to image data.\n");
             return false;
         }
     }
 
     // Return true on success
     return true;
 }
 
-bool SkBmpStandardCodec::initializeSwizzler(const SkImageInfo& dstInfo,
-                                            const Options& opts) {
+bool SkBmpStandardCodec::initializeSwizzler(const SkImageInfo& dstInfo, const Options& opts) {
     // Get swizzler configuration
     SkSwizzler::SrcConfig config;
     switch (this->bitsPerPixel()) {
         case 1:
             config = SkSwizzler::kIndex1;
             break;
         case 2:
             config = SkSwizzler::kIndex2;
             break;
         case 4:
@@ skipping 14 matching lines @@
             break;
         default:
             SkASSERT(false);
             return false;
     }
 
     // Get a pointer to the color table if it exists
     const SkPMColor* colorPtr = get_color_ptr(fColorTable.get());
 
     // Create swizzler
-    fSwizzler.reset(SkSwizzler::CreateSwizzler(config,
-            colorPtr, dstInfo, opts.fZeroInitialized));
+    fSwizzler.reset(SkSwizzler::CreateSwizzler(config, colorPtr, dstInfo, opts));
 
     if (nullptr == fSwizzler.get()) {
         return false;
     }
     return true;
 }
 
 SkCodec::Result SkBmpStandardCodec::prepareToDecode(const SkImageInfo& dstInfo,
         const SkCodec::Options& options, SkPMColor inputColorPtr[], int* inputColorCount) {
     // Create the color table if necessary and prepare the stream for decode
@@ skipping 79 matching lines @@
     return kSuccess;
 }
 
 uint32_t SkBmpStandardCodec::onGetFillValue(SkColorType colorType, SkAlphaType alphaType) const {
     const SkPMColor* colorPtr = get_color_ptr(fColorTable.get());
     if (colorPtr) {
         return get_color_table_fill_value(colorType, colorPtr, 0);
     }
     return INHERITED::onGetFillValue(colorType, alphaType);
 }