Fixes up dependencies and namespaces for tests in //third_party/http2/adapter.

PiperOrigin-RevId: 365628212
Change-Id: I72a41e334c2dfac980f52c223abe7cd7432f13fb
diff --git a/http2/adapter/test_utils_test.cc b/http2/adapter/test_utils_test.cc
index a000e5c..e8f4ebd 100644
--- a/http2/adapter/test_utils_test.cc
+++ b/http2/adapter/test_utils_test.cc
@@ -1,6 +1,6 @@
 #include "http2/adapter/test_utils.h"
 
-#include "testing/base/public/gunit.h"
+#include "common/platform/api/quiche_test.h"
 #include "spdy/core/spdy_framer.h"
 
 namespace http2 {