Revert of Delete SkImageDecoder (patchset #9 id:150001 of https://codereview.chromium.org/1820503002/ )

Reason for revert:
Roll still failing

Original issue's description:
> Delete SkImageDecoder
>
> This image decoding implementation has been replaced
> by SkCodec in Android.
>
> Additionally, we have replaced uses of SkImageDecoder
> in Skia and Google3 with uses of SkCodec.
>
> Now we can delete SkImageDecoder :).
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1820503002
> CQ_EXTRA_TRYBOTS=client.skia.compile:Build-Ubuntu-GCC-x86_64-Release-CMake-Trybot,Build-Mac-Clang-x86_64-Release-CMake-Trybot
>
> Committed: https://skia.googlesource.com/skia/+/f799706656f2581c5bf5510d94df3fa17cce1607
>
> Committed: https://skia.googlesource.com/skia/+/5b6e73e0c8282c4d85accbfbcecc6dee84f8a1eb
>
> Committed: https://skia.googlesource.com/skia/+/f037fdebda2a2626e6512d7532063f2cd41a264d

TBR=scroggo@google.com,djsollen@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1830943002

3 files changed, 542 insertions, 8 deletions

diff --git a/src/ports/SkImageDecoder_CG.cpp b/src/ports/SkImageDecoder_CG.cpp
index ead0ed6506..c4446ae16d 100644
--- a/src/ports/SkImageDecoder_CG.cpp
+++ b/src/ports/SkImageDecoder_CG.cpp
@@ -11,6 +11,7 @@
 #include "SkCGUtils.h"
 #include "SkColorPriv.h"
 #include "SkData.h"
+#include "SkImageDecoder.h"
 #include "SkImageEncoder.h"
 #include "SkMovie.h"
 #include "SkStream.h"
@@ -28,6 +29,210 @@
 #include <MobileCoreServices/MobileCoreServices.h>
 #endif
 
+static void data_unref_proc(void* skdata, const void*, size_t) {
+    SkASSERT(skdata);
+    static_cast<SkData*>(skdata)->unref();
+}
+
+static CGDataProviderRef SkStreamToDataProvider(SkStream* stream) {
+    // TODO: use callbacks, so we don't have to load all the data into RAM
+    SkData* skdata = SkCopyStreamToData(stream).release();
+    if (!skdata) {
+        return nullptr;
+    }
+
+    return CGDataProviderCreateWithData(skdata, skdata->data(), skdata->size(), data_unref_proc);
+}
+
+static CGImageSourceRef SkStreamToCGImageSource(SkStream* stream) {
+    CGDataProviderRef data = SkStreamToDataProvider(stream);
+    if (!data) {
+        return nullptr;
+    }
+    CGImageSourceRef imageSrc = CGImageSourceCreateWithDataProvider(data, 0);
+    CGDataProviderRelease(data);
+    return imageSrc;
+}
+
+class SkImageDecoder_CG : public SkImageDecoder {
+protected:
+    virtual Result onDecode(SkStream* stream, SkBitmap* bm, Mode);
+};
+
+static void argb_4444_force_opaque(void* row, int count) {
+    uint16_t* row16 = (uint16_t*)row;
+    for (int i = 0; i < count; ++i) {
+        row16[i] |= 0xF000;
+    }
+}
+
+static void argb_8888_force_opaque(void* row, int count) {
+    // can use RGBA or BGRA, they have the same shift for alpha
+    const uint32_t alphaMask = 0xFF << SK_RGBA_A32_SHIFT;
+    uint32_t* row32 = (uint32_t*)row;
+    for (int i = 0; i < count; ++i) {
+        row32[i] |= alphaMask;
+    }
+}
+
+static void alpha_8_force_opaque(void* row, int count) {
+    memset(row, 0xFF, count);
+}
+
+static void force_opaque(SkBitmap* bm) {
+    SkAutoLockPixels alp(*bm);
+    if (!bm->getPixels()) {
+        return;
+    }
+
+    void (*proc)(void*, int);
+    switch (bm->colorType()) {
+        case kARGB_4444_SkColorType:
+            proc = argb_4444_force_opaque;
+            break;
+        case kRGBA_8888_SkColorType:
+        case kBGRA_8888_SkColorType:
+            proc = argb_8888_force_opaque;
+            break;
+        case kAlpha_8_SkColorType:
+            proc = alpha_8_force_opaque;
+            break;
+        default:
+            return;
+    }
+
+    char* row = (char*)bm->getPixels();
+    for (int y = 0; y < bm->height(); ++y) {
+        proc(row, bm->width());
+        row += bm->rowBytes();
+    }
+    bm->setAlphaType(kOpaque_SkAlphaType);
+}
+
+#define BITMAP_INFO (kCGBitmapByteOrder32Big | kCGImageAlphaPremultipliedLast)
+
+class AutoCFDataRelease {
+    CFDataRef fDR;
+public:
+    AutoCFDataRelease(CFDataRef dr) : fDR(dr) {}
+    ~AutoCFDataRelease() { if (fDR) { CFRelease(fDR); } }
+
+    operator CFDataRef () { return fDR; }
+};
+
+static bool colorspace_is_sRGB(CGColorSpaceRef cs) {
+#ifdef SK_BUILD_FOR_IOS
+    return true;    // iOS seems to define itself to always return sRGB <reed>
+#else
+    AutoCFDataRelease data(CGColorSpaceCopyICCProfile(cs));
+    if (data) {
+        // found by inspection -- need a cleaner way to sniff a profile
+        const CFIndex ICC_PROFILE_OFFSET_TO_SRGB_TAG = 52;
+
+        if (CFDataGetLength(data) >= ICC_PROFILE_OFFSET_TO_SRGB_TAG + 4) {
+            return !memcmp(CFDataGetBytePtr(data) + ICC_PROFILE_OFFSET_TO_SRGB_TAG, "sRGB", 4);
+        }
+    }
+    return false;
+#endif
+}
+
+SkImageDecoder::Result SkImageDecoder_CG::onDecode(SkStream* stream, SkBitmap* bm, Mode mode) {
+    CGImageSourceRef imageSrc = SkStreamToCGImageSource(stream);
+
+    if (nullptr == imageSrc) {
+        return kFailure;
+    }
+    SkAutoTCallVProc<const void, CFRelease> arsrc(imageSrc);
+
+    CGImageRef image = CGImageSourceCreateImageAtIndex(imageSrc, 0, nullptr);
+    if (nullptr == image) {
+        return kFailure;
+    }
+    SkAutoTCallVProc<CGImage, CGImageRelease> arimage(image);
+
+    const int width = SkToInt(CGImageGetWidth(image));
+    const int height = SkToInt(CGImageGetHeight(image));
+    SkColorProfileType cpType = kLinear_SkColorProfileType;
+
+    CGColorSpaceRef cs = CGImageGetColorSpace(image);
+    if (cs) {
+        CGColorSpaceModel m = CGColorSpaceGetModel(cs);
+        if (kCGColorSpaceModelRGB == m && colorspace_is_sRGB(cs)) {
+            cpType = kSRGB_SkColorProfileType;
+        }
+    }
+
+    SkAlphaType at = kPremul_SkAlphaType;
+    switch (CGImageGetAlphaInfo(image)) {
+        case kCGImageAlphaNone:
+        case kCGImageAlphaNoneSkipLast:
+        case kCGImageAlphaNoneSkipFirst:
+            at = kOpaque_SkAlphaType;
+            break;
+        default:
+            break;
+    }
+
+    bm->setInfo(SkImageInfo::Make(width, height, kN32_SkColorType, at, cpType));
+    if (SkImageDecoder::kDecodeBounds_Mode == mode) {
+        return kSuccess;
+    }
+
+    if (!this->allocPixelRef(bm, nullptr)) {
+        return kFailure;
+    }
+
+    SkAutoLockPixels alp(*bm);
+
+    if (!SkCopyPixelsFromCGImage(bm->info(), bm->rowBytes(), bm->getPixels(), image)) {
+        return kFailure;
+    }
+
+    CGImageAlphaInfo info = CGImageGetAlphaInfo(image);
+    switch (info) {
+        case kCGImageAlphaNone:
+        case kCGImageAlphaNoneSkipLast:
+        case kCGImageAlphaNoneSkipFirst:
+            // We're opaque, but we can't rely on the data always having 0xFF
+            // in the alpha slot (which Skia wants), so we have to ram it in
+            // ourselves.
+            force_opaque(bm);
+            break;
+        default:
+            // we don't know if we're opaque or not, so compute it.
+            if (SkBitmap::ComputeIsOpaque(*bm)) {
+                bm->setAlphaType(kOpaque_SkAlphaType);
+            }
+    }
+    if (!bm->isOpaque() && this->getRequireUnpremultipliedColors()) {
+        // CGBitmapContext does not support unpremultiplied, so the image has been premultiplied.
+        // Convert to unpremultiplied.
+        for (int i = 0; i < width; ++i) {
+            for (int j = 0; j < height; ++j) {
+                uint32_t* addr = bm->getAddr32(i, j);
+                *addr = SkUnPreMultiply::UnPreMultiplyPreservingByteOrder(*addr);
+            }
+        }
+        bm->setAlphaType(kUnpremul_SkAlphaType);
+    }
+    return kSuccess;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+extern SkImageDecoder* image_decoder_from_stream(SkStreamRewindable*);
+
+SkImageDecoder* SkImageDecoder::Factory(SkStreamRewindable* stream) {
+    SkImageDecoder* decoder = image_decoder_from_stream(stream);
+    if (nullptr == decoder) {
+        // If no image decoder specific to the stream exists, use SkImageDecoder_CG.
+        return new SkImageDecoder_CG;
+    } else {
+        return decoder;
+    }
+}
+
 /////////////////////////////////////////////////////////////////////////
 
 SkMovie* SkMovie::DecodeStream(SkStreamRewindable* stream) {
@@ -150,13 +355,57 @@ static SkImageEncoder* sk_imageencoder_cg_factory(SkImageEncoder::Type t) {
 
 static SkImageEncoder_EncodeReg gEReg(sk_imageencoder_cg_factory);
 
-class SkPNGImageEncoder_CG : public SkImageEncoder_CG {
+#ifdef SK_BUILD_FOR_IOS
+class SkPNGImageEncoder_IOS : public SkImageEncoder_CG {
 public:
-    SkPNGImageEncoder_CG()
+    SkPNGImageEncoder_IOS()
         : SkImageEncoder_CG(kPNG_Type) {
     }
 };
 
-DEFINE_ENCODER_CREATOR(PNGImageEncoder_CG);
+DEFINE_ENCODER_CREATOR(PNGImageEncoder_IOS);
+#endif
+
+struct FormatConversion {
+    CFStringRef             fUTType;
+    SkImageDecoder::Format  fFormat;
+};
+
+// Array of the types supported by the decoder.
+static const FormatConversion gFormatConversions[] = {
+    { kUTTypeBMP, SkImageDecoder::kBMP_Format },
+    { kUTTypeGIF, SkImageDecoder::kGIF_Format },
+    { kUTTypeICO, SkImageDecoder::kICO_Format },
+    { kUTTypeJPEG, SkImageDecoder::kJPEG_Format },
+    // Also include JPEG2000
+    { kUTTypeJPEG2000, SkImageDecoder::kJPEG_Format },
+    { kUTTypePNG, SkImageDecoder::kPNG_Format },
+};
+
+static SkImageDecoder::Format UTType_to_Format(const CFStringRef uttype) {
+    for (size_t i = 0; i < SK_ARRAY_COUNT(gFormatConversions); i++) {
+        if (CFStringCompare(uttype, gFormatConversions[i].fUTType, 0) == kCFCompareEqualTo) {
+            return gFormatConversions[i].fFormat;
+        }
+    }
+    return SkImageDecoder::kUnknown_Format;
+}
+
+static SkImageDecoder::Format get_format_cg(SkStreamRewindable* stream) {
+    CGImageSourceRef imageSrc = SkStreamToCGImageSource(stream);
+
+    if (nullptr == imageSrc) {
+        return SkImageDecoder::kUnknown_Format;
+    }
+
+    SkAutoTCallVProc<const void, CFRelease> arsrc(imageSrc);
+    const CFStringRef name = CGImageSourceGetType(imageSrc);
+    if (nullptr == name) {
+        return SkImageDecoder::kUnknown_Format;
+    }
+    return UTType_to_Format(name);
+}
+
+static SkImageDecoder_FormatReg gFormatReg(get_format_cg);
 
 #endif//defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_IOS)
diff --git a/src/ports/SkImageDecoder_WIC.cpp b/src/ports/SkImageDecoder_WIC.cpp
index 43068fc8f6..5febd856d6 100644
--- a/src/ports/SkImageDecoder_WIC.cpp
+++ b/src/ports/SkImageDecoder_WIC.cpp
@@ -31,6 +31,7 @@
 
 #include <wincodec.h>
 #include "SkAutoCoInitialize.h"
+#include "SkImageDecoder.h"
 #include "SkImageEncoder.h"
 #include "SkIStream.h"
 #include "SkMovie.h"
@@ -47,6 +48,222 @@
 #undef CLSID_WICImagingFactory
 #endif
 
+class SkImageDecoder_WIC : public SkImageDecoder {
+public:
+    // Decoding modes corresponding to SkImageDecoder::Mode, plus an extra mode for decoding
+    // only the format.
+    enum WICModes {
+        kDecodeFormat_WICMode,
+        kDecodeBounds_WICMode,
+        kDecodePixels_WICMode,
+    };
+
+    /**
+     *  Helper function to decode an SkStream.
+     *  @param stream SkStream to decode. Must be at the beginning.
+     *  @param bm   SkBitmap to decode into. Only used if wicMode is kDecodeBounds_WICMode or
+     *      kDecodePixels_WICMode, in which case it must not be nullptr.
+     *  @param format Out parameter for the SkImageDecoder::Format of the SkStream. Only used if
+     *      wicMode is kDecodeFormat_WICMode.
+     */
+    bool decodeStream(SkStream* stream, SkBitmap* bm, WICModes wicMode, Format* format) const;
+
+protected:
+    Result onDecode(SkStream* stream, SkBitmap* bm, Mode mode) override;
+};
+
+struct FormatConversion {
+    GUID                    fGuidFormat;
+    SkImageDecoder::Format  fFormat;
+};
+
+static const FormatConversion gFormatConversions[] = {
+    { GUID_ContainerFormatBmp, SkImageDecoder::kBMP_Format },
+    { GUID_ContainerFormatGif, SkImageDecoder::kGIF_Format },
+    { GUID_ContainerFormatIco, SkImageDecoder::kICO_Format },
+    { GUID_ContainerFormatJpeg, SkImageDecoder::kJPEG_Format },
+    { GUID_ContainerFormatPng, SkImageDecoder::kPNG_Format },
+};
+
+static SkImageDecoder::Format GuidContainerFormat_to_Format(REFGUID guid) {
+    for (size_t i = 0; i < SK_ARRAY_COUNT(gFormatConversions); i++) {
+        if (IsEqualGUID(guid, gFormatConversions[i].fGuidFormat)) {
+            return gFormatConversions[i].fFormat;
+        }
+    }
+    return SkImageDecoder::kUnknown_Format;
+}
+
+SkImageDecoder::Result SkImageDecoder_WIC::onDecode(SkStream* stream, SkBitmap* bm, Mode mode) {
+    WICModes wicMode;
+    switch (mode) {
+        case SkImageDecoder::kDecodeBounds_Mode:
+            wicMode = kDecodeBounds_WICMode;
+            break;
+        case SkImageDecoder::kDecodePixels_Mode:
+            wicMode = kDecodePixels_WICMode;
+            break;
+    }
+    return this->decodeStream(stream, bm, wicMode, nullptr) ? kSuccess : kFailure;
+}
+
+bool SkImageDecoder_WIC::decodeStream(SkStream* stream, SkBitmap* bm, WICModes wicMode,
+                                      Format* format) const {
+    //Initialize COM.
+    SkAutoCoInitialize scopedCo;
+    if (!scopedCo.succeeded()) {
+        return false;
+    }
+
+    HRESULT hr = S_OK;
+
+    //Create Windows Imaging Component ImagingFactory.
+    SkTScopedComPtr<IWICImagingFactory> piImagingFactory;
+    if (SUCCEEDED(hr)) {
+        hr = CoCreateInstance(
+            CLSID_WICImagingFactory
+            , nullptr
+            , CLSCTX_INPROC_SERVER
+            , IID_PPV_ARGS(&piImagingFactory)
+        );
+    }
+
+    //Convert SkStream to IStream.
+    SkTScopedComPtr<IStream> piStream;
+    if (SUCCEEDED(hr)) {
+        hr = SkIStream::CreateFromSkStream(stream, false, &piStream);
+    }
+
+    //Make sure we're at the beginning of the stream.
+    if (SUCCEEDED(hr)) {
+        LARGE_INTEGER liBeginning = { 0 };
+        hr = piStream->Seek(liBeginning, STREAM_SEEK_SET, nullptr);
+    }
+
+    //Create the decoder from the stream content.
+    SkTScopedComPtr<IWICBitmapDecoder> piBitmapDecoder;
+    if (SUCCEEDED(hr)) {
+        hr = piImagingFactory->CreateDecoderFromStream(
+            piStream.get()                    //Image to be decoded
+            , nullptr                            //No particular vendor
+            , WICDecodeMetadataCacheOnDemand  //Cache metadata when needed
+            , &piBitmapDecoder                //Pointer to the decoder
+        );
+    }
+
+    if (kDecodeFormat_WICMode == wicMode) {
+        SkASSERT(format != nullptr);
+        //Get the format
+        if (SUCCEEDED(hr)) {
+            GUID guidFormat;
+            hr = piBitmapDecoder->GetContainerFormat(&guidFormat);
+            if (SUCCEEDED(hr)) {
+                *format = GuidContainerFormat_to_Format(guidFormat);
+                return true;
+            }
+        }
+        return false;
+    }
+
+    //Get the first frame from the decoder.
+    SkTScopedComPtr<IWICBitmapFrameDecode> piBitmapFrameDecode;
+    if (SUCCEEDED(hr)) {
+        hr = piBitmapDecoder->GetFrame(0, &piBitmapFrameDecode);
+    }
+
+    //Get the BitmapSource interface of the frame.
+    SkTScopedComPtr<IWICBitmapSource> piBitmapSourceOriginal;
+    if (SUCCEEDED(hr)) {
+        hr = piBitmapFrameDecode->QueryInterface(
+            IID_PPV_ARGS(&piBitmapSourceOriginal)
+        );
+    }
+
+    //Get the size of the bitmap.
+    UINT width;
+    UINT height;
+    if (SUCCEEDED(hr)) {
+        hr = piBitmapSourceOriginal->GetSize(&width, &height);
+    }
+
+    //Exit early if we're only looking for the bitmap bounds.
+    if (SUCCEEDED(hr)) {
+        bm->setInfo(SkImageInfo::MakeN32Premul(width, height));
+        if (kDecodeBounds_WICMode == wicMode) {
+            return true;
+        }
+        if (!this->allocPixelRef(bm, nullptr)) {
+            return false;
+        }
+    }
+
+    //Create a format converter.
+    SkTScopedComPtr<IWICFormatConverter> piFormatConverter;
+    if (SUCCEEDED(hr)) {
+        hr = piImagingFactory->CreateFormatConverter(&piFormatConverter);
+    }
+
+    GUID destinationPixelFormat;
+    if (this->getRequireUnpremultipliedColors()) {
+        destinationPixelFormat = GUID_WICPixelFormat32bppBGRA;
+    } else {
+        destinationPixelFormat = GUID_WICPixelFormat32bppPBGRA;
+    }
+
+    if (SUCCEEDED(hr)) {
+        hr = piFormatConverter->Initialize(
+            piBitmapSourceOriginal.get()      //Input bitmap to convert
+            , destinationPixelFormat          //Destination pixel format
+            , WICBitmapDitherTypeNone         //Specified dither patterm
+            , nullptr                            //Specify a particular palette
+            , 0.f                             //Alpha threshold
+            , WICBitmapPaletteTypeCustom      //Palette translation type
+        );
+    }
+
+    //Get the BitmapSource interface of the format converter.
+    SkTScopedComPtr<IWICBitmapSource> piBitmapSourceConverted;
+    if (SUCCEEDED(hr)) {
+        hr = piFormatConverter->QueryInterface(
+            IID_PPV_ARGS(&piBitmapSourceConverted)
+        );
+    }
+
+    //Copy the pixels into the bitmap.
+    if (SUCCEEDED(hr)) {
+        SkAutoLockPixels alp(*bm);
+        bm->eraseColor(SK_ColorTRANSPARENT);
+        const UINT stride = (UINT) bm->rowBytes();
+        hr = piBitmapSourceConverted->CopyPixels(
+            nullptr,                             //Get all the pixels
+            stride,
+            stride * height,
+            reinterpret_cast<BYTE *>(bm->getPixels())
+        );
+
+        // Note: we don't need to premultiply here since we specified PBGRA
+        if (SkBitmap::ComputeIsOpaque(*bm)) {
+            bm->setAlphaType(kOpaque_SkAlphaType);
+        }
+    }
+
+    return SUCCEEDED(hr);
+}
+
+/////////////////////////////////////////////////////////////////////////
+
+extern SkImageDecoder* image_decoder_from_stream(SkStreamRewindable*);
+
+SkImageDecoder* SkImageDecoder::Factory(SkStreamRewindable* stream) {
+    SkImageDecoder* decoder = image_decoder_from_stream(stream);
+    if (nullptr == decoder) {
+        // If no image decoder specific to the stream exists, use SkImageDecoder_WIC.
+        return new SkImageDecoder_WIC;
+    } else {
+        return decoder;
+    }
+}
+
 /////////////////////////////////////////////////////////////////////////
 
 SkMovie* SkMovie::DecodeStream(SkStreamRewindable* stream) {
@@ -58,10 +275,6 @@ SkMovie* SkMovie::DecodeStream(SkStreamRewindable* stream) {
 class SkImageEncoder_WIC : public SkImageEncoder {
 public:
     SkImageEncoder_WIC(Type t) : fType(t) {}
-    
-    // DO NOT USE this constructor.  This exists only so SkForceLinking can
-    // link the WIC image encoder.
-    SkImageEncoder_WIC() {}
 
 protected:
     virtual bool onEncode(SkWStream* stream, const SkBitmap& bm, int quality);
@@ -241,6 +454,15 @@ static SkImageEncoder* sk_imageencoder_wic_factory(SkImageEncoder::Type t) {
 
 static SkImageEncoder_EncodeReg gEReg(sk_imageencoder_wic_factory);
 
-DEFINE_ENCODER_CREATOR(ImageEncoder_WIC);
+static SkImageDecoder::Format get_format_wic(SkStreamRewindable* stream) {
+    SkImageDecoder::Format format;
+    SkImageDecoder_WIC codec;
+    if (!codec.decodeStream(stream, nullptr, SkImageDecoder_WIC::kDecodeFormat_WICMode, &format)) {
+        format = SkImageDecoder::kUnknown_Format;
+    }
+    return format;
+}
+
+static SkImageDecoder_FormatReg gFormatReg(get_format_wic);
 
 #endif // defined(SK_BUILD_FOR_WIN32)
diff --git a/src/ports/SkImageDecoder_empty.cpp b/src/ports/SkImageDecoder_empty.cpp
index 33e07acea6..f52dada73b 100644
--- a/src/ports/SkImageDecoder_empty.cpp
+++ b/src/ports/SkImageDecoder_empty.cpp
@@ -8,11 +8,74 @@
 
 #include "SkBitmap.h"
 #include "SkImage.h"
+#include "SkImageDecoder.h"
 #include "SkImageEncoder.h"
 #include "SkMovie.h"
 #include "SkPixelSerializer.h"
 #include "SkStream.h"
 
+class SkColorTable;
+class SkPngChunkReader;
+
+// Empty implementations for SkImageDecoder.
+
+SkImageDecoder::SkImageDecoder() {}
+
+SkImageDecoder::~SkImageDecoder() {}
+
+SkImageDecoder* SkImageDecoder::Factory(SkStreamRewindable*) {
+    return nullptr;
+}
+
+void SkImageDecoder::copyFieldsToOther(SkImageDecoder* ) {}
+
+bool SkImageDecoder::DecodeFile(const char[], SkBitmap*, SkColorType, Mode, Format*) {
+    return false;
+}
+
+SkImageDecoder::Result SkImageDecoder::decode(SkStream*, SkBitmap*, SkColorType, Mode) {
+    return kFailure;
+}
+
+bool SkImageDecoder::DecodeStream(SkStreamRewindable*, SkBitmap*, SkColorType, Mode, Format*) {
+    return false;
+}
+
+bool SkImageDecoder::DecodeMemory(const void*, size_t, SkBitmap*, SkColorType, Mode, Format*) {
+    return false;
+}
+
+bool SkImageDecoder::decodeYUV8Planes(SkStream*, SkISize[3], void*[3],
+                                      size_t[3], SkYUVColorSpace*) {
+    return false;
+}
+
+SkImageDecoder::Format SkImageDecoder::getFormat() const {
+    return kUnknown_Format;
+}
+
+SkImageDecoder::Format SkImageDecoder::GetStreamFormat(SkStreamRewindable*) {
+    return kUnknown_Format;
+}
+
+const char* SkImageDecoder::GetFormatName(Format) {
+    return nullptr;
+}
+
+SkPngChunkReader* SkImageDecoder::setPeeker(SkPngChunkReader*) {
+    return nullptr;
+}
+
+SkBitmap::Allocator* SkImageDecoder::setAllocator(SkBitmap::Allocator*) {
+    return nullptr;
+}
+
+void SkImageDecoder::setSampleSize(int) {}
+
+bool SkImageDecoder::allocPixelRef(SkBitmap*, SkColorTable*) const {
+    return false;
+}
+
 /////////////////////////////////////////////////////////////////////////
 
 // Empty implementation for SkMovie.