Add SkEncodedInfo to report properties of encoded image data

src/codec/SkCodec.cpp

Index: src/codec/SkCodec.cpp
diff --git a/src/codec/SkCodec.cpp b/src/codec/SkCodec.cpp
index 7bc831a6ac52f027265a556d29a1b8e3acce3a14..e46551ff78f2f1c82940b7847b60545329b107fd 100644
--- a/src/codec/SkCodec.cpp
+++ b/src/codec/SkCodec.cpp
@@ -114,9 +114,10 @@ SkCodec* SkCodec::NewFromData(SkData* data, SkPngChunkReader* reader) {
     return NewFromStream(new SkMemoryStream(data), reader);
 }
 
-SkCodec::SkCodec(const SkImageInfo& info, SkStream* stream, sk_sp<SkColorSpace> colorSpace,
+SkCodec::SkCodec(const SkEncodedInfo& info, SkStream* stream, sk_sp<SkColorSpace> colorSpace,
         Origin origin)
-    : fSrcInfo(info)
+    : fEncodedInfo(info)
+    , fSrcInfo(info.makeImageInfo())

[scroggo, 2016/03/23 14:48:50]

Alternatively, we could lazily create this when asked for. We would need to
change getInfo() to stop returning a reference, and how SkCodecImageGenerater
deals with it, so it would be a bigger change. If we do go that route, it should
be its own change, I think.

[msarett, 2016/03/24 16:20:44]

SGTM.

The reason that I did it this way is that, when I'm the client, I call getInfo()
over and over again (expecting it to be free).  I didn't want to force us to
create a new SkImageInfo on each call.

Another option would be to create an SkImageInfo on the first call and reuse it
on subsequent calls, but that may be unnecessarily complex.

     , fStream(stream)
     , fNeedsRewind(false)
     , fColorSpace(colorSpace)