remove dead SK_SUPPORT_LEGACY_IMAGEDECODER_CHOOSER code

src/images/SkImageDecoder_libpng.cpp

 /*
  * Copyright 2006 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 "SkImageDecoder.h"
 #include "SkImageEncoder.h"
 #include "SkColor.h"
@@ skipping 596 matching lines @@
 
     // sanity check for size
     {
         int64_t size = sk_64_mul(origWidth, origHeight);
         // now check that if we are 4-bytes per pixel, we also don't overflow
         if (size < 0 || size > (0x7FFFFFFF >> 2)) {
             return false;
         }
     }
 
-#ifdef SK_SUPPORT_LEGACY_IMAGEDECODER_CHOOSER
-    if (!this->chooseFromOneChoice(*colorTypep, origWidth, origHeight)) {
-        return false;
-    }
-#endif
-
     // If the image has alpha and the decoder wants unpremultiplied
     // colors, the only supported colortype is 8888.
     if (this->getRequireUnpremultipliedColors() && *hasAlphap) {
         *colorTypep = kN32_SkColorType;
     }
 
     if (fImageIndex != NULL) {
         if (kUnknown_SkColorType == fImageIndex->fColorType) {
             // This is the first time for this subset decode. From now on,
             // all decodes must be in the same colortype.
@@ skipping 642 matching lines @@
     return SkImageDecoder::kUnknown_Format;
 }
 
 SkImageEncoder* sk_libpng_efactory(SkImageEncoder::Type t) {
     return (SkImageEncoder::kPNG_Type == t) ? SkNEW(SkPNGImageEncoder) : NULL;
 }
 
 static SkImageDecoder_DecodeReg gDReg(sk_libpng_dfactory);
 static SkImageDecoder_FormatReg gFormatReg(get_format_png);
 static SkImageEncoder_EncodeReg gEReg(sk_libpng_efactory);