Modify SkPngCodec to recognize 565 images from the sBIT chunk

src/codec/SkPngCodec.cpp

Index: src/codec/SkPngCodec.cpp
diff --git a/src/codec/SkPngCodec.cpp b/src/codec/SkPngCodec.cpp
index 60f7b9b866518dc5ee6679f0a8a1028524417f61..c110fde605ec811882891aca41c17c5e1e977c0f 100644
--- a/src/codec/SkPngCodec.cpp
+++ b/src/codec/SkPngCodec.cpp
@@ -706,6 +706,16 @@ static bool read_header(SkStream* stream, SkPngChunkReader* chunkReader, SkCodec
             alpha = SkEncodedInfo::kUnpremul_Alpha;
     }
 
+    // Add a special check for 565.
+    if (SkEncodedInfo::kOpaque_Alpha == alpha) {
+        png_color_8p sigBits;
+        if (png_get_sBIT(png_ptr, info_ptr, &sigBits)) {
+            if (5 == sigBits->red && 6 == sigBits->green && 5 == sigBits->blue) {
+                color = SkEncodedInfo::k565_Color;
+            }
+        }
+    }
+
     int numberPasses = png_set_interlace_handling(png_ptr);
 
     autoClean.release();