hide Config in SkImageDecoder -- use SkColorType instead

src/images/SkDecodingImageGenerator.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 "SkData.h"
 #include "SkDecodingImageGenerator.h"
 #include "SkImageDecoder.h"
@@ skipping 155 matching lines @@
         return false;
     }
     decoder->setDitherImage(fDitherImage);
     decoder->setSampleSize(fSampleSize);
     decoder->setRequireUnpremultipliedColors(
             info.fAlphaType == kUnpremul_SkAlphaType);
 
     SkBitmap bitmap;
     TargetAllocator allocator(fInfo, pixels, rowBytes);
     decoder->setAllocator(&allocator);
-    // TODO: need to be able to pass colortype directly to decoder
-    SkBitmap::Config legacyConfig = SkColorTypeToBitmapConfig(info.colorType());
-    bool success = decoder->decode(fStream, &bitmap, legacyConfig,
+    bool success = decoder->decode(fStream, &bitmap, info.colorType(),
                                    SkImageDecoder::kDecodePixels_Mode);
     decoder->setAllocator(NULL);
     if (!success) {
         return false;
     }
     if (allocator.isReady()) {  // Did not use pixels!
         SkBitmap bm;
         SkASSERT(bitmap.canCopyTo(info.colorType()));
         bool copySuccess = bitmap.copyTo(&bm, info.colorType(), &allocator);
         if (!copySuccess || allocator.isReady()) {
@@ skipping 85 matching lines @@
         SkStreamRewindable* stream,
         const SkDecodingImageGenerator::Options& opts) {
     SkASSERT(stream != NULL);
     SkASSERT(stream->unique());
     if ((stream == NULL) || !stream->unique()) {
         SkSafeUnref(stream);
         return NULL;
     }
     return CreateDecodingImageGenerator(NULL, stream, opts);
 }