Change SkImageDecoders to take an SkStreamRewindable.

src/images/SkImageDecoder_libico.cpp

Index: src/images/SkImageDecoder_libico.cpp
diff --git a/src/images/SkImageDecoder_libico.cpp b/src/images/SkImageDecoder_libico.cpp
index c0f0f91edfc5c60ebe6039bdf886bf3a84901c7d..2b65a36c76f3fe8bce69aac4a075495aa1271967 100644
--- a/src/images/SkImageDecoder_libico.cpp
+++ b/src/images/SkImageDecoder_libico.cpp
@@ -383,7 +383,7 @@ static void editPixelBit32(const int pixelNo, const unsigned char* buf,
 DEFINE_DECODER_CREATOR(ICOImageDecoder);
 /////////////////////////////////////////////////////////////////////////////////////////
 
-static bool is_ico(SkStream* stream) {
+static bool is_ico(SkStreamRewindable* stream) {
     // Check to see if the first four bytes are 0,0,1,0
     // FIXME: Is that required and sufficient?
     SkAutoMalloc autoMal(4);
@@ -398,7 +398,7 @@ static bool is_ico(SkStream* stream) {
     return true;
 }
 
-static SkImageDecoder* sk_libico_dfactory(SkStream* stream) {
+static SkImageDecoder* sk_libico_dfactory(SkStreamRewindable* stream) {
     if (is_ico(stream)) {
         return SkNEW(SkICOImageDecoder);
     }
@@ -407,7 +407,7 @@ static SkImageDecoder* sk_libico_dfactory(SkStream* stream) {
 
 static SkImageDecoder_DecodeReg gReg(sk_libico_dfactory);
 
-static SkImageDecoder::Format get_format_ico(SkStream* stream) {
+static SkImageDecoder::Format get_format_ico(SkStreamRewindable* stream) {
     if (is_ico(stream)) {
         return SkImageDecoder::kICO_Format;
     }