util/net: Place death tests into a *DeathTest test case

util/net/http_multipart_builder_test.cc

Index: util/net/http_multipart_builder_test.cc
diff --git a/util/net/http_multipart_builder_test.cc b/util/net/http_multipart_builder_test.cc
index b4fae5b83740c2fec61b838e0aabfec783504f8b..761580e7b20536fd49b0dce2630adb7e467c815f 100644
--- a/util/net/http_multipart_builder_test.cc
+++ b/util/net/http_multipart_builder_test.cc
@@ -248,7 +248,7 @@ TEST(HTTPMultipartBuilder, SharedFormDataAndAttachmentKeyNamespace) {
   EXPECT_EQ(lines.end(), lines_it);
 }
 
-TEST(HTTPMultipartBuilder, AssertUnsafeMIMEType) {
+TEST(HTTPMultipartBuilderDeathTest, AssertUnsafeMIMEType) {
   HTTPMultipartBuilder builder;
   // Invalid and potentially dangerous:
   ASSERT_DEATH(builder.SetFileAttachment("", "", base::FilePath(), "\r\n"), "");