Resize images for hi-dpi based on a custom PNG chunk added by GRIT r78, and roll GRIT r78

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 <string>
 #include <vector>
 
@@ skipping 99 matching lines @@
                      int* w, int* h);
 
   // Decodes the PNG data directly into the passed in SkBitmap. This is
   // significantly faster than the vector<unsigned char> version of Decode()
   // above when dealing with PNG files that are >500K, which a lot of theme
   // images are. (There are a lot of themes that have a NTP image of about ~1
   // megabyte, and those require a 7-10 megabyte side buffer.)
   //
   // Returns true if data is non-null and can be decoded as a png, false
   // otherwise.
+  //
+  // If the call succeeds and |fell_back_to_1x| is not NULL, it is set to true
+  // if Chrome's custom csCl PNG chunk is present (indicating that GRIT fell
+  // back to the 100% image), false if not.
+  static bool Decode(const unsigned char* input, size_t input_size,
+                     SkBitmap* bitmap, bool* fell_back_to_1x);
+
+  // Equivalent to Decode(input, input_size, bitmap, NULL), for clients that
+  // don't need fell_back_to_1x returned (which is most clients).
   static bool Decode(const unsigned char* input, size_t input_size,
                      SkBitmap* bitmap);
 
   // Create a SkBitmap from a decoded BGRA DIB. The caller owns the returned
   // SkBitmap.
   static SkBitmap* CreateSkBitmapFromBGRAFormat(
       std::vector<unsigned char>& bgra, int width, int height);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PNGCodec);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_CODEC_PNG_CODEC_H_