Add reallyHasAlpha() to SkAndroidCodec

src/codec/SkAndroidCodec.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 "SkAndroidCodec.h"
 #include "SkCodec.h"
 #include "SkCodecPriv.h"
 #include "SkSampledCodec.h"
 #include "SkWebpAdapterCodec.h"
 
 static bool is_valid_sample_size(int sampleSize) {
     // FIXME: As Leon has mentioned elsewhere, surely there is also a maximum sampleSize?
     return sampleSize > 0;
 }
 
-SkAndroidCodec::SkAndroidCodec(const SkImageInfo& info)
-    : fInfo(info)
+SkAndroidCodec::SkAndroidCodec(SkCodec* codec)
+    : fInfo(codec->getInfo())
+    , fCodec(codec)
 {}
 
 SkAndroidCodec* SkAndroidCodec::NewFromStream(SkStream* stream, SkPngChunkReader* chunkReader) {
     SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream, chunkReader));
     if (nullptr == codec) {
         return nullptr;
     }
 
     switch (codec->getEncodedFormat()) {
         case kWEBP_SkEncodedFormat:
@@ skipping 90 matching lines @@
         }
     }
 
     return this->onGetAndroidPixels(info, pixels, rowBytes, *options);
 }
 
 SkCodec::Result SkAndroidCodec::getAndroidPixels(const SkImageInfo& info, void* pixels,
         size_t rowBytes) {
     return this->getAndroidPixels(info, pixels, rowBytes, nullptr);
 }