Modify SkPngCodec to recognize 565 images from the sBIT chunk

src/codec/SkSwizzler.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCodecPriv.h"
 #include "SkColorPriv.h"
 #include "SkOpts.h"
@@ skipping 786 matching lines @@
                                 break;
                             default:
                                 return nullptr;
                         }
                         break;
                     default:
                         return nullptr;
                 }
                 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 have a hint that there are only 5/6 "significant" bits.
                 switch (dstInfo.colorType()) {
                     case kRGBA_8888_SkColorType:
                         proc = &swizzle_rgb_to_rgba;
                         fastProc = &fast_swizzle_rgb_to_rgba;
                         break;
                     case kBGRA_8888_SkColorType:
                         proc = &swizzle_rgb_to_bgra;
                         fastProc = &fast_swizzle_rgb_to_bgra;
                         break;
                     case kRGB_565_SkColorType:
@@ skipping 219 matching lines @@
     }
 
     return fAllocatedWidth;
 }
 
 void SkSwizzler::swizzle(void* dst, const uint8_t* SK_RESTRICT src) {
     SkASSERT(nullptr != dst && nullptr != src);
     fActualProc(SkTAddOffset<void>(dst, fDstOffsetBytes), src, fSwizzleWidth, fSrcBPP,
             fSampleX * fSrcBPP, fSrcOffsetUnits, fColorTable);
 }