Add support for multiple frames in SkCodec

src/codec/SkCodec.cpp

Index: src/codec/SkCodec.cpp
diff --git a/src/codec/SkCodec.cpp b/src/codec/SkCodec.cpp
index 84afc2bdee282b598b76f6f75234d276339712e6..644f3e27a7d61730340d0b029fe5ecb669a4ec7f 100644
--- a/src/codec/SkCodec.cpp
+++ b/src/codec/SkCodec.cpp
@@ -34,9 +34,7 @@ static const DecoderProc gDecoderProcs[] = {
 #ifdef SK_HAS_WEBP_LIBRARY
     { SkWebpCodec::IsWebp, SkWebpCodec::NewFromStream },
 #endif
-#ifdef SK_HAS_GIF_LIBRARY
     { SkGifCodec::IsGif, SkGifCodec::NewFromStream },
-#endif
 #ifdef SK_HAS_PNG_LIBRARY
     { SkIcoCodec::IsIco, SkIcoCodec::NewFromStream },
 #endif
@@ -142,12 +140,6 @@ SkCodec::SkCodec(const SkEncodedInfo& info, const SkImageInfo& imageInfo, SkStre
 SkCodec::~SkCodec() {}
 
 bool SkCodec::rewindIfNeeded() {
-    if (!fStream) {
-        // Some codecs do not have a stream.  They may hold onto their own data or another codec.
-        // They must handle rewinding themselves.
-        return true;
-    }
-
     // Store the value of fNeedsRewind so we can update it. Next read will
     // require a rewind.
     const bool needsRewind = fNeedsRewind;
@@ -161,7 +153,9 @@ bool SkCodec::rewindIfNeeded() {
     // startIncrementalDecode will need to be called before incrementalDecode.
     fStartedIncrementalDecode = false;
 
-    if (!fStream->rewind()) {
+    // Some codecs do not have a stream.  They may hold onto their own data or another codec.
+    // They must handle rewinding themselves.
+    if (fStream && !fStream->rewind()) {
         return false;
     }
 
@@ -472,14 +466,5 @@ void SkCodec::fillIncompleteImage(const SkImageInfo& info, void* dst, size_t row
             fill_proc(fillInfo, fillDst, rowBytes, fillValue, zeroInit, sampler);
             break;
         }
-        case kOutOfOrder_SkScanlineOrder: {
-            SkASSERT(1 == linesRequested || this->getInfo().height() == linesRequested);
-            const SkImageInfo fillInfo = info.makeWH(fillWidth, 1);
-            for (int srcY = linesDecoded; srcY < linesRequested; srcY++) {
-                fillDst = SkTAddOffset<void>(dst, this->outputScanline(srcY) * rowBytes);
-                fill_proc(fillInfo, fillDst, rowBytes, fillValue, zeroInit, sampler);
-            }
-            break;
-        }
     }
 }