Move calls to conversion_possible to SkCodec

Move common code into the base class, so subclasses need not call
conversion_possible.

Use SkEncodedInfo rather than SkImageInfo, and use the proper frame.

API Changes:
- SkAndroidCodec:
  - Add getEncodedInfo(), for SkBitmapRegionCodec
- SkEncodedInfo:
  - Add opaque() helper
- SkBitmapRegionDecoder:
  - Remove unused conversionSupported

(Split off from skia-review.googlesource.com/c/25746)

Bug: skia:5601
Change-Id: If4a40d4b98a3dd0afde2b6058f92315a393a5baf
Reviewed-on: https://skia-review.googlesource.com/34361
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: Derek Sollenberger <djsollen@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>

3 files changed, 11 insertions, 1 deletions

diff --git a/include/codec/SkAndroidCodec.h b/include/codec/SkAndroidCodec.h
index 3571108edd..cc93bf18c4 100644
--- a/include/codec/SkAndroidCodec.h
+++ b/include/codec/SkAndroidCodec.h
@@ -41,8 +41,9 @@ public:
      */
     static std::unique_ptr<SkAndroidCodec> MakeFromData(sk_sp<SkData>, SkPngChunkReader* = nullptr);
 
-    virtual ~SkAndroidCodec() {}
+    virtual ~SkAndroidCodec();
 
+    const SkEncodedInfo& getEncodedInfo() const;
 
     const SkImageInfo& getInfo() const { return fInfo; }
 
diff --git a/include/codec/SkCodec.h b/include/codec/SkCodec.h
index fb4f165dbf..8ec44c8539 100644
--- a/include/codec/SkCodec.h
+++ b/include/codec/SkCodec.h
@@ -846,6 +846,13 @@ private:
     bool                               fStartedIncrementalDecode;
 
     /**
+     *  Return whether {srcColor, srcIsOpaque, srcCS} can convert to dst.
+     *
+     *  Will be called for the appropriate frame, prior to initializing the colorXform.
+     */
+    virtual bool conversionSupported(const SkImageInfo& dst, SkEncodedInfo::Color srcColor,
+                                     bool srcIsOpaque, const SkColorSpace* srcCS) const;
+    /**
      *  Return whether these dimensions are supported as a scale.
      *
      *  The codec may choose to cache the information about scale and subset.
diff --git a/include/codec/SkEncodedInfo.h b/include/codec/SkEncodedInfo.h
index 3b1ce48713..dce88cadc1 100644
--- a/include/codec/SkEncodedInfo.h
+++ b/include/codec/SkEncodedInfo.h
@@ -156,6 +156,8 @@ public:
 
     Color color() const { return fColor; }
     Alpha alpha() const { return fAlpha; }
+    bool opaque() const { return fAlpha == kOpaque_Alpha; }
+
     uint8_t bitsPerComponent() const { return fBitsPerComponent; }
 
     uint8_t bitsPerPixel() const {