Move the chromeHidden.toJSON paranoia out of event.js and into json.js, a new

chrome/renderer/extensions/json_js_unittest.cc

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/test/base/module_system_test.h"
+#include "grit/renderer_resources.h"
+
+namespace extensions {
+namespace {
+
+// Tests chrome/renderer/resources/json.js.
+class JsonJsTest : public ModuleSystemTest {
+  virtual void SetUp() OVERRIDE {
+    ModuleSystemTest::SetUp();
+    RegisterModule("json", IDR_JSON_JS);
+  }
+
+ protected:
+  std::string requires() {
+    return
+      "var assert = requireNative('assert');"

[koz (OOO until 15th September), 2013/02/19 23:19:08]

Nit: if you add \n to your lines you get line numbers in your exceptions.

[not at google - send to devlin, 2013/02/19 23:52:13]

Done.

+      "var json = require('json');";
+  }
+
+  std::string test_body() {
+    return
+      "var str = '{\"a\":1,\"b\":true,\"c\":[\"hi\"]}';"
+      "var obj = json.parse(str);"
+      "assert.AssertTrue(json.stringify(obj) === str);"
+      "assert.AssertTrue(obj.a === 1);"
+      "assert.AssertTrue(obj.b === true);"
+      "assert.AssertTrue(obj.c.length === 1);"
+      "assert.AssertTrue(obj.c[0] === 'hi');";
+  }
+};
+
+TEST_F(JsonJsTest, NoOverrides) {
+  ModuleSystem::NativesEnabledScope natives_enabled_scope(module_system_.get());
+  RegisterModule("test", requires() + test_body());
+  module_system_->Require("test");
+}
+
+TEST_F(JsonJsTest, EverythingOverridden) {
+  ModuleSystem::NativesEnabledScope natives_enabled_scope(module_system_.get());
+  std::string overrides =
+    "function fakeToJSON() { throw '42'; }"
+    "Object.prototype.toJSON = fakeToJSON;"
+    "Array.prototype.toJSON = fakeToJSON;"
+    "Number.prototype.toJSON = fakeToJSON;"
+    "Boolean.prototype.toJSON = fakeToJSON;"
+    "String.prototype.toJSON = fakeToJSON;";
+  RegisterModule("test", requires() + overrides + test_body());

[koz (OOO until 15th September), 2013/02/19 23:19:08]

Cool test :-)

You may want to test that after the json.parse() call the user-overridden
toJSON()s are preserved.

[not at google - send to devlin, 2013/02/19 23:52:13]

Done.

[not at google - send to devlin, 2013/02/19 23:52:13]

Done.

+  module_system_->Require("test");
+}
+
+}  // namespace
+}  // namespace extensions