hide Config in SkImageDecoder -- use SkColorType instead

src/image/SkImagePriv.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkImagePriv.h"
 #include "SkCanvas.h"
 #include "SkPicture.h"
@@ skipping 15 matching lines @@
         case kIndex_8_SkColorType:
             return SkBitmap::kIndex8_Config;
 
         default:
             // break for unsupported colortypes
             break;
     }
     return SkBitmap::kNo_Config;
 }
 
-SkBitmap::Config SkImageInfoToBitmapConfig(const SkImageInfo& info) {
-    return SkColorTypeToBitmapConfig(info.fColorType);
-}
-
 SkColorType SkBitmapConfigToColorType(SkBitmap::Config config) {
     static const SkColorType gCT[] = {
         kUnknown_SkColorType,   // kNo_Config
         kAlpha_8_SkColorType,   // kA8_Config
         kIndex_8_SkColorType,   // kIndex8_Config
         kRGB_565_SkColorType,   // kRGB_565_Config
         kARGB_4444_SkColorType, // kARGB_4444_Config
         kN32_SkColorType,   // kARGB_8888_Config
     };
     SkASSERT((unsigned)config < SK_ARRAY_COUNT(gCT));
@@ skipping 11 matching lines @@
         image = SkNewImageFromPixelRef(info, bm.pixelRef(), bm.rowBytes());
     } else {
         bm.lockPixels();
         if (bm.getPixels()) {
             image = SkImage::NewRasterCopy(info, bm.getPixels(), bm.rowBytes());
         }
         bm.unlockPixels();
     }
     return image;
 }