Remove final third_party/gtest reference.

Missed this in https://github.com/bazelbuild/bazel/commit/8e9f4a8591d65c7972aea3957c57601570e0a39b.

RELNOTES: None.
PiperOrigin-RevId: 190506543
diff --git a/src/test/cpp/util/BUILD b/src/test/cpp/util/BUILD
index 6fb3d5c..aed5d77 100644
--- a/src/test/cpp/util/BUILD
+++ b/src/test/cpp/util/BUILD
@@ -99,7 +99,7 @@
     deps = select({
         "//src/conditions:windows": [
             ":windows_test_util",
-            "//third_party:gtest",
+            "@com_google_googletest//:gtest_main",
         ],
         "//conditions:default": [],
     }),
diff --git a/src/test/cpp/util/windows_test_util_test.cc b/src/test/cpp/util/windows_test_util_test.cc
index e408246..d777a91 100644
--- a/src/test/cpp/util/windows_test_util_test.cc
+++ b/src/test/cpp/util/windows_test_util_test.cc
@@ -15,7 +15,7 @@
 
 #include <string>
 
-#include "gtest/gtest.h"
+#include "googletest/include/gtest/gtest.h"
 #include "src/test/cpp/util/windows_test_util.h"
 
 #if !defined(COMPILER_MSVC) && !defined(__CYGWIN__)