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

ui/gfx/codec/png_codec_unittest.cc

 // Copyright (c) 2012 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.
 
 #if defined(USE_SYSTEM_LIBPNG)
 #include <png.h>
 #else
 #include "third_party/libpng/png.h"
 #endif
 
@@ skipping 891 matching lines @@
 }
 
 // Test that corrupted data decompression causes failures.
 TEST(PNGCodec, DecodeCorrupted) {
   int w = 20, h = 20;
 
   // Make some random data (an uncompressed image).
   std::vector<unsigned char> original;
   MakeRGBImage(w, h, &original);
 
-  // It should fail when given non-JPEG compressed data.
+  // It should fail when given non-PNG compressed data.
   std::vector<unsigned char> output;
   int outw, outh;
   EXPECT_FALSE(PNGCodec::Decode(&original[0], original.size(),
                                 PNGCodec::FORMAT_RGB, &output,
                                 &outw, &outh));
 
   // Make some compressed data.
   std::vector<unsigned char> compressed;
   ASSERT_TRUE(PNGCodec::Encode(&original[0], PNGCodec::FORMAT_RGB,
                                Size(w, h), w * 3, false,
@@ skipping 199 matching lines @@
                                PNGCodec::FORMAT_RGBA, &decoded,
                                &outw, &outh));
   ASSERT_EQ(w, outw);
   ASSERT_EQ(h, outh);
   ASSERT_EQ(original.size(), decoded.size());
 
   // Images must be exactly equal
   ASSERT_TRUE(original == decoded);
 }
 
+TEST(PNGCodec, CustomScaleChunkDetection) {
+  const int w = 20, h = 20;
+  static const unsigned char png_scale_chunk[12] =
+      { 0, 0, 0, 0, 'c', 's', 'C', 'l', 0xc1, 0x30, 0x60, 0x4d };
+
+  // Compress some random data.
+  SkBitmap original;
+  std::vector<unsigned char> compressed;
+  MakeTestSkBitmap(w, h, &original);
+  PNGCodec::EncodeBGRASkBitmap(original, false, &compressed);
+
+  // Without the custom chunk, fell_back_to_1x should be false.
+  SkBitmap decompressed;
+  bool fell_back_to_1x = true;
+  EXPECT_TRUE(PNGCodec::Decode(&compressed[0], compressed.size(),
+                               &decompressed, &fell_back_to_1x));
+  EXPECT_FALSE(fell_back_to_1x);
+
+  // With the custom chunk, fell_back_to_1x should be true.
+  compressed.insert(compressed.end() - 12,
+                    png_scale_chunk, png_scale_chunk + sizeof(png_scale_chunk));
+  fell_back_to_1x = false;
+  EXPECT_TRUE(PNGCodec::Decode(&compressed[0], compressed.size(),
+                               &decompressed, &fell_back_to_1x));
+  EXPECT_TRUE(fell_back_to_1x);
+}
+
 
 }  // namespace gfx