Safely handle unsupported color xforms in SkCodec

(1) The transformation code *should* support any src SkColorSpace
that we successfully parse.  This is agreed upon internally and
by clients.  The fact that we currently don't is just a bug...
(2) We cannot and will not support all SkColorSpaces as dsts.

So if we fail to make a SkColorSpaceXform, we should assume that
it was caused by a bad dst color space.  The correct response in
this case is to return kInvalidConversion.  I've rewritten the CL
to do this.

The fact that weird src spaces will sometimes trigger a
kInvalidConversion is just a bug that is being actively worked on.

TBR=reed@google.com

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=3661

Change-Id: Iac2b45120507ec71b1b3d555c61931f7348dad9e
Reviewed-on: https://skia-review.googlesource.com/3661
Commit-Queue: Matt Sarett <msarett@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>
Reviewed-by: Robert Aftias <raftias@google.com>

1 files changed, 15 insertions, 9 deletions

diff --git a/include/codec/SkCodec.h b/include/codec/SkCodec.h
index 363347dd72..153eaa9b42 100644
--- a/include/codec/SkCodec.h
+++ b/include/codec/SkCodec.h
@@ -19,6 +19,7 @@
 #include "SkYUVSizeInfo.h"
 
 class SkColorSpace;
+class SkColorSpaceXform;
 class SkData;
 class SkPngChunkReader;
 class SkSampler;
@@ -706,25 +707,30 @@ protected:
 
     virtual int onOutputScanline(int inputScanline) const;
 
+    bool initializeColorXform(const SkImageInfo& dstInfo);
+    SkColorSpaceXform* colorXform() const { return fColorXform.get(); }
+
     /**
      *  Used for testing with qcms.
      *  FIXME: Remove this when we are done comparing with qcms.
      */
     virtual sk_sp<SkData> getICCData() const { return nullptr; }
+
 private:
-    const SkEncodedInfo         fEncodedInfo;
-    const SkImageInfo           fSrcInfo;
-    SkAutoTDelete<SkStream>     fStream;
-    bool                        fNeedsRewind;
-    const Origin                fOrigin;
+    const SkEncodedInfo                fEncodedInfo;
+    const SkImageInfo                  fSrcInfo;
+    SkAutoTDelete<SkStream>            fStream;
+    bool                               fNeedsRewind;
+    const Origin                       fOrigin;
 
-    SkImageInfo                 fDstInfo;
-    SkCodec::Options            fOptions;
+    SkImageInfo                        fDstInfo;
+    SkCodec::Options                   fOptions;
+    std::unique_ptr<SkColorSpaceXform> fColorXform;
 
     // Only meaningful during scanline decodes.
-    int                         fCurrScanline;
+    int                                fCurrScanline;
 
-    bool                        fStartedIncrementalDecode;
+    bool                               fStartedIncrementalDecode;
 
     /**
      *  Return whether these dimensions are supported as a scale.