Delete reallyHasAlpha() from SkCodec

src/codec/SkSampledCodec.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 "SkCodec.h"
 #include "SkCodecPriv.h"
 #include "SkMath.h"
 #include "SkSampledCodec.h"
+#include "SkSampler.h"
 #include "SkTemplates.h"
 
 SkSampledCodec::SkSampledCodec(SkCodec* codec)
     : INHERITED(codec)
 {}
 
 SkISize SkSampledCodec::accountForNativeScaling(int* sampleSizePtr, int* nativeSampleSize) const {
     SkISize preSampledSize = this->codec()->getInfo().dimensions();
     int sampleSize = *sampleSizePtr;
     SkASSERT(sampleSize > 1);
@@ skipping 266 matching lines @@
                 // this->codec() has already handled filling uninitialized memory.
                 return SkCodec::kIncompleteInput;
             }
             return SkCodec::kSuccess;
         }
         default:
             SkASSERT(false);
             return SkCodec::kUnimplemented;
     }
 }