Disable another racy HostResolverImplTest under tsan.

net/dns/host_resolver_impl_unittest.cc

Index: net/dns/host_resolver_impl_unittest.cc
diff --git a/net/dns/host_resolver_impl_unittest.cc b/net/dns/host_resolver_impl_unittest.cc
index 5d19fdcda120187acff86f6392db0bbe9e9e40ab..1eb4ee029b736957f7e2783401d337952bf7222e 100644
--- a/net/dns/host_resolver_impl_unittest.cc
+++ b/net/dns/host_resolver_impl_unittest.cc
@@ -621,7 +621,16 @@ TEST_F(HostResolverImplTest, EmptyHost) {
   EXPECT_EQ(ERR_NAME_NOT_RESOLVED, req->Resolve());
 }
 
-TEST_F(HostResolverImplTest, EmptyDotsHost) {
+#if defined(THREAD_SANITIZER)
+// There's a data race in this test that may lead to use-after-free.
+// If the test starts to crash without ThreadSanitizer it needs to be disabled
+// globally. See http://crbug.com/268946 (stacks for this test in
+// crbug.com/333567).
+#define MAYBE_EmptyDotsHost DISABLED_EmptyDotsHost
+#else
+#define MAYBE_EmptyDotsHost EmptyDotsHost
+#endif
+TEST_F(HostResolverImplTest, MAYBE_EmptyDotsHost) {
   for (int i = 0; i < 16; ++i) {
     Request* req = CreateRequest(std::string(i, '.'), 5555);
     EXPECT_EQ(ERR_NAME_NOT_RESOLVED, req->Resolve());