Revert "Add native_testing library to mock @Native classes"

tests/html/js_interop_constructor_name_test_js.js

Index: tests/html/js_interop_constructor_name_test_js.js
diff --git a/tests/html/js_interop_constructor_name_test_js.js b/tests/html/js_interop_constructor_name_test_js.js
deleted file mode 100644
index 828cbc94779de9f66179bfde60dbd1891d8890e4..0000000000000000000000000000000000000000
--- a/tests/html/js_interop_constructor_name_test_js.js
+++ /dev/null
@@ -1,20 +0,0 @@
-(function() {
-
-  // A constructor function with the same name as a HTML element.
-  function HTMLDivElement(a) {
-    this.a = a;
-  }
-
-  HTMLDivElement.prototype.bar = function() {
-    return this.a;
-  }
-
-  HTMLDivElement.prototype.toString = function() {
-    return "HTMLDivElement(" + this.a + ")";
-  }
-
-  self.makeDiv = function(text) {
-    return new HTMLDivElement(text);
-  };
-
-})();