Rewrite SkTRegistry to take any trivially-copyable type.

src/images/SkImageDecoder_libpng.cpp

Index: src/images/SkImageDecoder_libpng.cpp
diff --git a/src/images/SkImageDecoder_libpng.cpp b/src/images/SkImageDecoder_libpng.cpp
index c188a2fabc4ef93c21c899c7a6173b053bcc93ee..c6638d718d689b42796f94d704a9cc676a04a50b 100644
--- a/src/images/SkImageDecoder_libpng.cpp
+++ b/src/images/SkImageDecoder_libpng.cpp
@@ -1203,6 +1203,6 @@ SkImageEncoder* sk_libpng_efactory(SkImageEncoder::Type t) {
     return (SkImageEncoder::kPNG_Type == t) ? SkNEW(SkPNGImageEncoder) : NULL;
 }
 
-static SkTRegistry<SkImageEncoder*, SkImageEncoder::Type> gEReg(sk_libpng_efactory);
-static SkTRegistry<SkImageDecoder::Format, SkStream*> gFormatReg(get_format_png);
-static SkTRegistry<SkImageDecoder*, SkStream*> gDReg(sk_libpng_dfactory);
+static SkTRegistry<SkImageEncoder*(*)(SkImageEncoder::Type)> gEReg(sk_libpng_efactory);
+static SkTRegistry<SkImageDecoder::Format(*)(SkStream*)> gFormatReg(get_format_png);

[reed1, 2013/09/04 15:15:23]

Seems like (perhaps) ImageDecoder should typedef this signature, just to make it
easy for all of its clients to "get it right".

[scroggo, 2013/09/04 15:40:21]

That sounds reasonable to me.

+static SkTRegistry<SkImageDecoder*(*)(SkStream*)> gDReg(sk_libpng_dfactory);