Modify SkPngCodec to recognize 565 images from the sBIT chunk

src/codec/SkSwizzler.cpp

Index: src/codec/SkSwizzler.cpp
diff --git a/src/codec/SkSwizzler.cpp b/src/codec/SkSwizzler.cpp
index c9eb923053879809706ceec392444136181729e6..ec17a03ae1074cf46cc6e6ad0df4dc1b5239e4fb 100644
--- a/src/codec/SkSwizzler.cpp
+++ b/src/codec/SkSwizzler.cpp
@@ -804,6 +804,10 @@ SkSwizzler* SkSwizzler::CreateSwizzler(const SkEncodedInfo& encodedInfo,
                 }
                 break;
             case SkEncodedInfo::kRGB_Color:
+            case SkEncodedInfo::k565_Color:
+                // Treat 565 exactly like RGB (since it's still encoded as 8 bits per component).
+                // We just mark as 565 when we have a hint that there are only 5/6/5 "significant"
+                // bits in each channel.
                 switch (dstInfo.colorType()) {
                     case kRGBA_8888_SkColorType:
                         proc = &swizzle_rgb_to_rgba;