[libfuzzer] improving gfx_png_image_fuzzer

testing/libfuzzer/fuzzers/gfx_png_image_fuzzer.cc

Index: testing/libfuzzer/fuzzers/gfx_png_image_fuzzer.cc
diff --git a/testing/libfuzzer/fuzzers/gfx_png_image_fuzzer.cc b/testing/libfuzzer/fuzzers/gfx_png_image_fuzzer.cc
index f7161592af242b08ca73717b71e00ac7c2778e2d..82a072f80d3d383be56d71f854c83ba826b6b832 100644
--- a/testing/libfuzzer/fuzzers/gfx_png_image_fuzzer.cc
+++ b/testing/libfuzzer/fuzzers/gfx_png_image_fuzzer.cc
@@ -9,7 +9,13 @@
 
 // Entry point for LibFuzzer.
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  gfx::Image::CreateFrom1xPNGBytes(data, size);
+  gfx::Image image = gfx::Image::CreateFrom1xPNGBytes(data, size);
+
+  if (image.IsEmpty())
+    return 0;
+
+  image.ToSkBitmap();
+
   return 0;
 }