Add SkEncodedInfo to report properties of encoded image data

src/codec/SkJpegDecoderMgr.cpp

Index: src/codec/SkJpegDecoderMgr.cpp
diff --git a/src/codec/SkJpegDecoderMgr.cpp b/src/codec/SkJpegDecoderMgr.cpp
index cc44f3c42117cd1b285ee5651180f47bd2b602df..d91c627ab642f2af0b390f16bc8bc008c3b095ca 100644
--- a/src/codec/SkJpegDecoderMgr.cpp
+++ b/src/codec/SkJpegDecoderMgr.cpp
@@ -34,12 +34,20 @@ SkCodec::Result JpegDecoderMgr::returnFailure(const char caller[], SkCodec::Resu
     return result;
 }
 
-SkColorType JpegDecoderMgr::getColorType() {
+SkEncodedInfo::Color JpegDecoderMgr::getEncodedColor() {
     switch (fDInfo.jpeg_color_space) {
         case JCS_GRAYSCALE:
-            return kGray_8_SkColorType;
+            return SkEncodedInfo::kGray_Color;
+        case JCS_YCbCr:
+            return SkEncodedInfo::kYUV_Color;
+        case JCS_RGB:
+            return SkEncodedInfo::kRGB_Color;
+        case JCS_YCCK:
+            return SkEncodedInfo::kYCCK_Color;
+        case JCS_CMYK:
+            return SkEncodedInfo::kInvertedCMYK_Color;
         default:
-            return kN32_SkColorType;
+            return SkEncodedInfo::kYUV_Color;

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

What types fall into the default case? Why not be explicit?

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

Other JPEG_COLOR_SPACES include RGBA, BGRA, 565 etc. but these should never the
be the encoded color_space.  They would indicate a bug in libjpeg-turbo.

The only other "valid" value would be JCS_UNKNOWN.  And we would get this if
there is a really strange number of components 2, 5, 6...

In this case the decode will fail because we cannot do color conversion (unless
we call jpeg_read_raw_data(), which we won't, because we only use this for YUV
images).

Still I should handle this more clearly and fail faster...

     }
 }