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

Index: ui/gfx/codec/png_codec_unittest.cc
diff --git a/ui/gfx/codec/png_codec_unittest.cc b/ui/gfx/codec/png_codec_unittest.cc
index 83f535e6ae3e4d7a0180b516ca5cbda7516d34b1..c7b5b80995dc8cd1e8d0714172546e1c72b4cdba 100644
--- a/ui/gfx/codec/png_codec_unittest.cc
+++ b/ui/gfx/codec/png_codec_unittest.cc
@@ -909,7 +909,7 @@ TEST(PNGCodec, DecodeCorrupted) {
   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(),
@@ -1129,5 +1129,32 @@ TEST(PNGCodec, EncodeDecodeWithVaryingCompressionLevels) {
   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, scale_fallback should be false.
+  SkBitmap decompressed;
+  bool scale_fallback = true;
+  EXPECT_TRUE(PNGCodec::Decode(&compressed[0], compressed.size(),
+                               &decompressed, &scale_fallback));
+  EXPECT_FALSE(scale_fallback);
+
+  // With the custom chunk, scale_fallback should be true.
+  compressed.insert(compressed.end() - 12,
+                    png_scale_chunk, png_scale_chunk + sizeof(png_scale_chunk));
+  scale_fallback = false;
+  EXPECT_TRUE(PNGCodec::Decode(&compressed[0], compressed.size(),
+                               &decompressed, &scale_fallback));
+  EXPECT_TRUE(scale_fallback);
+}
+
 
 }  // namespace gfx