Add support for writing unit tests for Mojo-backed apps/extensions APIs.

extensions/renderer/resources/test_custom_bindings_delegate.js

+// Copyright 2014 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.
+
+var chrome = requireNative('chrome').GetChrome();
+var GetExtensionAPIDefinitionsForTest =
+    requireNative('apiDefinitions').GetExtensionAPIDefinitionsForTest;
+var GetAPIFeatures = requireNative('test_features').GetAPIFeatures;
+var userGestures = requireNative('user_gestures');
+
+var RunWithNativesEnabledModuleSystem =
+    requireNative('v8_context').RunWithNativesEnabledModuleSystem;
+
+function registerHooks(api, runTests) {
+  var chromeTest = api.compiledApi;
+  var apiFunctions = api.apiFunctions;
+
+  apiFunctions.setHandleRequest('runTests', function(tests) {
+    runTests(tests);
+  });
+
+  apiFunctions.setHandleRequest('runWithModuleSystem', function(callback) {
+    RunWithNativesEnabledModuleSystem(callback);
+  });
+
+  apiFunctions.setHandleRequest('getApiDefinitions', function() {
+    return GetExtensionAPIDefinitionsForTest();
+  });
+
+  apiFunctions.setHandleRequest('getApiFeatures', function() {
+    return GetAPIFeatures();
+  });
+
+  apiFunctions.setHandleRequest('isProcessingUserGesture', function() {
+    return userGestures.IsProcessingUserGesture();
+  });
+
+  apiFunctions.setHandleRequest('runWithUserGesture', function(callback) {
+    chromeTest.assertEq(typeof(callback), 'function');
+    return userGestures.RunWithUserGesture(callback);
+  });
+
+  apiFunctions.setHandleRequest('runWithoutUserGesture', function(callback) {
+    chromeTest.assertEq(typeof(callback), 'function');
+    return userGestures.RunWithoutUserGesture(callback);
+  });
+
+}
+
+function testDone(runNextTest) {
+  // Use setTimeout here to allow previous test contexts to be
+  // eligible for garbage collection.
+  setTimeout(runNextTest, 0);
+}
+
+exports.registerHooks = registerHooks;
+exports.testDone = testDone;