Expose more info in SkCodec::FrameInfo

Bug: b/160984428

Add more fields to SkCodec::FrameInfo, which describes the properties of
an individual frame in an animated image. This allows a client that
wishes to seek to determine frame dependencies so that they can decode
an arbitrary frame, which in turn will allow SkCodec to remove
SkCodec::FrameInfo::fRequiredFrame. Currently, SkCodec seeks through the
stream to determine frame dependencies, but this is unnecessary work
(and storage) for a client that does not want to seek.

These fields also support the proposed APIs in go/animated-ndk.

Move SkCodecAnimation::Blend from SkCodecAnimationPriv (and delete that
file) into SkCodecAnimation.h. Rename its values to be more clear.

Merge common code for populating SkCodec::FrameInfo.

Add a test for a GIF with offsets outside the range of the image. Note
that libwebp rejects such an image.

Update libgifcodec.

Change-Id: Ie27e0531e7d62eaae153eccb3105bf2121b5aac4
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/339857
Commit-Queue: Leon Scroggins <scroggo@google.com>
Reviewed-by: Derek Sollenberger <djsollen@google.com>
Reviewed-by: Nigel Tao <nigeltao@google.com>
diff --git a/src/codec/SkHeifCodec.cpp b/src/codec/SkHeifCodec.cpp
index 1c83481..2a162e8 100644
--- a/src/codec/SkHeifCodec.cpp
+++ b/src/codec/SkHeifCodec.cpp
@@ -348,11 +348,7 @@
     }
 
     if (frameInfo) {
-        frameInfo->fRequiredFrame = SkCodec::kNoFrame;
-        frameInfo->fDuration = frame->getDuration();
-        frameInfo->fFullyReceived = true;
-        frameInfo->fAlphaType = kOpaque_SkAlphaType;
-        frameInfo->fDisposalMethod = SkCodecAnimation::DisposalMethod::kKeep;
+        frame->fillIn(frameInfo, true);
     }
 
     return true;