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>

1 files changed, 1 insertions, 3 deletions

diff --git a/src/codec/SkGifCodec.cpp b/src/codec/SkGifCodec.cpp
index d54cbd558e..4bd0e17bd0 100644
--- a/src/codec/SkGifCodec.cpp
+++ b/src/codec/SkGifCodec.cpp
@@ -228,9 +228,7 @@ SkCodec::Result SkGifCodec::prepareToDecode(const SkImageInfo& dstInfo, const Op
 
     const auto at = frame->hasAlpha() ? kUnpremul_SkAlphaType : kOpaque_SkAlphaType;
     const auto srcInfo = this->getInfo().makeAlphaType(at);
-    if (!conversion_possible(dstInfo, srcInfo) ||
-        !this->initializeColorXform(dstInfo, opts.fPremulBehavior))
-    {
+    if (!this->initializeColorXform(dstInfo, opts.fPremulBehavior)) {
         return gif_error("Cannot convert input type to output type.\n", kInvalidConversion);
     }