Support more swizzles to 565 in SkCodec

src/codec/SkCodec_libgif.cpp

Index: src/codec/SkCodec_libgif.cpp
diff --git a/src/codec/SkCodec_libgif.cpp b/src/codec/SkCodec_libgif.cpp
index cf935777d18ef2ad6fd388ee80055166a7042e7d..bd64a3f4dac2656ab2e1522b2be6d89eb5a41747 100644
--- a/src/codec/SkCodec_libgif.cpp
+++ b/src/codec/SkCodec_libgif.cpp
@@ -211,30 +211,6 @@ SkGifCodec::SkGifCodec(const SkImageInfo& srcInfo, SkStream* stream,
 {}
 
 /*
- * Checks if the conversion between the input image and the requested output
- * image has been implemented
- */
-static bool conversion_possible(const SkImageInfo& dst,
-                                const SkImageInfo& src) {
-    // Ensure that the profile type is unchanged
-    if (dst.profileType() != src.profileType()) {
-        return false;
-    }
-
-    // Check for supported color and alpha types
-    switch (dst.colorType()) {
-        case kN32_SkColorType:
-            return kPremul_SkAlphaType == dst.alphaType() ||
-                    kUnpremul_SkAlphaType == dst.alphaType();
-        case kIndex_8_SkColorType:
-            return kPremul_SkAlphaType == dst.alphaType() ||
-                    kUnpremul_SkAlphaType == dst.alphaType();
-        default:
-            return false;
-    }
-}
-
-/*
  * Initiates the gif decode
  */
 SkCodec::Result SkGifCodec::onGetPixels(const SkImageInfo& dstInfo,