Use SkPngEncoder in gfx jpeg_codec

ui/gfx/codec/png_codec.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_GFX_CODEC_PNG_CODEC_H_
 #define UI_GFX_CODEC_PNG_CODEC_H_
 
 #include <stddef.h>
 
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "ui/gfx/codec/codec_export.h"
 
 class SkBitmap;
 
 namespace gfx {
 
 class Size;
 
 // Interface for encoding and decoding PNG data. This is a wrapper around
 // libpng, which has an inconvenient interface for callers. This is currently
 // designed for use in tests only (where we control the files), so the handling
 // isn't as robust as would be required for a browser (see Decode() for more).
 // WebKit has its own more complicated PNG decoder which handles, among other
 // things, partially downloaded data.
 class CODEC_EXPORT PNGCodec {
  public:
+  static constexpr int DEFAULT_ZLIB_COMPRESSION = 6;
+
   enum ColorFormat {
     // 4 bytes per pixel, in RGBA order in memory regardless of endianness.
     FORMAT_RGBA,
 
     // 4 bytes per pixel, in BGRA order in memory regardless of endianness.
     // This is the default Windows DIB order.
     FORMAT_BGRA,
 
     // SkBitmap format. For Encode() kARGB_8888_Config (4 bytes per pixel) and
     // kA8_Config (1 byte per pixel) formats are supported. kA8_Config gets
@@ skipping 81 matching lines @@
   static bool Decode(const unsigned char* input, size_t input_size,
                      SkBitmap* bitmap);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PNGCodec);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_CODEC_PNG_CODEC_H_