Rewrite SkTRegistry to take any trivially-copyable type.

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 47fa7293f0a54b5410d8f361da4a23577d468479..be8437ff8b81b5e3fe1c384b53721c03f412fa44 100644
--- a/src/images/SkImageDecoder_libico.cpp
+++ b/src/images/SkImageDecoder_libico.cpp
@@ -407,7 +407,7 @@ static SkImageDecoder* sk_libico_dfactory(SkStream* stream) {
     return NULL;
 }
 
-static SkTRegistry<SkImageDecoder*, SkStream*> gReg(sk_libico_dfactory);
+static SkTRegistry<SkImageDecoder*(*)(SkStream*)> gReg(sk_libico_dfactory);
 
 static SkImageDecoder::Format get_format_ico(SkStream* stream) {
     if (is_ico(stream)) {
@@ -416,4 +416,4 @@ static SkImageDecoder::Format get_format_ico(SkStream* stream) {
     return SkImageDecoder::kUnknown_Format;
 }
 
-static SkTRegistry<SkImageDecoder::Format, SkStream*> gFormatReg(get_format_ico);
+static SkTRegistry<SkImageDecoder::Format(*)(SkStream*)> gFormatReg(get_format_ico);