Fix compile issue of jpeg decoder unit tests

content/common/gpu/media/vaapi_jpeg_decoder_unittest.cc

Index: content/common/gpu/media/vaapi_jpeg_decoder_unittest.cc
diff --git a/content/common/gpu/media/vaapi_jpeg_decoder_unittest.cc b/content/common/gpu/media/vaapi_jpeg_decoder_unittest.cc
index 8c4486193582894b493fd447a7ab5fc203671a33..b7043484cd94c8227a288dc642da66c7a1a9be71 100644
--- a/content/common/gpu/media/vaapi_jpeg_decoder_unittest.cc
+++ b/content/common/gpu/media/vaapi_jpeg_decoder_unittest.cc
@@ -46,7 +46,7 @@ class VaapiJpegDecoderTest : public ::testing::Test {
         << "failed to read input data from " << input_file.value();
   }
 
-  void TearDown() override { wrapper_.reset(); }
+  void TearDown() override { wrapper_ = nullptr; }
 
   bool VerifyDecode(const media::JpegParseResult& parse_result,
                     const std::string& md5sum);