Update PIEX version and adjust the RAW codec accordingly

src/codec/SkRawCodec.cpp

 /*
  * Copyright 2016 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 "SkColorPriv.h"
@@ skipping 622 matching lines @@
     } else {
         rawStream.reset(new SkRawBufferedStream(stream));
     }
 
     // Does not take the ownership of rawStream.
     SkPiexStream piexStream(rawStream.get());
     ::piex::PreviewImageData imageData;
     if (::piex::IsRaw(&piexStream)) {
         ::piex::Error error = ::piex::GetPreviewImageData(&piexStream, &imageData);
 
-        if (error == ::piex::Error::kOk && imageData.preview.length > 0) {
+        //  Theoretically PIEX can return JPEG compressed image or uncompressed RGB image. We only
+        //  handle the JPEG compressed preview image here.
+        if (error == ::piex::Error::kOk && imageData.preview.length > 0 &&
+            imageData.preview.format == ::piex::Image::kJpegCompressed)
+        {
             // transferBuffer() is destructive to the rawStream. Abandon the rawStream after this
             // function call.
             // FIXME: one may avoid the copy of memoryStream and use the buffered rawStream.
             SkMemoryStream* memoryStream =
                 rawStream->transferBuffer(imageData.preview.offset, imageData.preview.length);
             return memoryStream ? SkJpegCodec::NewFromStream(memoryStream) : nullptr;
         } else if (error == ::piex::Error::kFail) {
             return nullptr;
         }
     }
@@ skipping 101 matching lines @@
     SkISize sizeFloor = this->onGetScaledDimensions(1.f / std::floor(fullShortEdge / shortEdge));
     SkISize sizeCeil = this->onGetScaledDimensions(1.f / std::ceil(fullShortEdge / shortEdge));
     return sizeFloor == dim || sizeCeil == dim;
 }
 
 SkRawCodec::~SkRawCodec() {}
 
 SkRawCodec::SkRawCodec(SkDngImage* dngImage)
     : INHERITED(dngImage->getImageInfo(), nullptr)
     , fDngImage(dngImage) {}