Fix include guards of files in src/ios.

ios/web/public/test/web_view_interaction_test_util.h

Index: ios/web/public/test/web_view_interaction_test_util.h
diff --git a/ios/web/public/test/web_view_interaction_test_util.h b/ios/web/public/test/web_view_interaction_test_util.h
index 4edc1170f62e0413b6b857c11a2ec24be5a94180..a3c54d817f6fc0536e6f8b65222c28bb17e7533c 100644
--- a/ios/web/public/test/web_view_interaction_test_util.h
+++ b/ios/web/public/test/web_view_interaction_test_util.h
@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#ifndef IOS_WEB_PUBLIC_TEST_WEB_VIEW_INTERACTION_TEST_UTIL_H_
+#define IOS_WEB_PUBLIC_TEST_WEB_VIEW_INTERACTION_TEST_UTIL_H_
+
 #import <UIKit/UIKit.h>
 
 #include <string>
@@ -43,3 +46,5 @@ bool SubmitWebViewFormWithId(web::WebState* web_state,
                              const std::string& form_id);
 }  // namespace test
 }  // namespace web
+
+#endif  // IOS_WEB_PUBLIC_TEST_WEB_VIEW_INTERACTION_TEST_UTIL_H_