Add browser_test for extension app API with missing schema

chrome/test/data/extensions/api_test/stubs_app/background.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 apiFeatures = chrome.test.getApiFeatures();
+
+// Returns a list of all chrome.foo.bar API paths available to an app.
+function getApiPaths() {
+  var apiPaths = [];
+  var apiDefinitions = chrome.test.getApiDefinitions();
+  apiDefinitions.forEach(function(module) {
+    var namespace = module.namespace;
+
+    // Skip internal APIs.
+    if (apiFeatures[namespace].internal)
+      return;
+
+    // Get the API functions and events.
+    ["functions", "events"].forEach(function(section) {

[not at google - send to devlin, 2014/05/03 00:12:43]

it would be cleaner to loop over [module.functions, module.events] here.

[James Cook, 2014/05/05 16:36:26]

Done.

+      if (typeof(module[section]) == "undefined")
+        return;
+      module[section].forEach(function(entry) {
+        apiPaths.push(namespace + "." + entry.name);
+      });
+    });
+
+    // Get the API properties.
+    if (module.properties) {
+      Object.getOwnPropertyNames(module.properties).forEach(function(propName) {
+        apiPaths.push(namespace + "." + propName);
+      });
+    }
+  });
+  return apiPaths;
+}
+
+// Tests whether all parts of an API path can be accessed. The path is a
+// namespace or function/property/event etc. within a namespace, and is
+// dot-separated.
+function testPath(path) {
+  var parts = path.split('.');
+
+  var module = chrome;
+  for (var i = 0; i < parts.length; i++) {
+    // Touch this component of the path. This will die if an API does not have
+    // a schema registered.
+    module = module[parts[i]];
+
+    // The component should be defined unless it is lastError, which depends on
+    // there being an error.
+    if (typeof(module) == "undefined" && path != "runtime.lastError")
+      return false;
+  }
+  return true;
+}
+
+function doTest() {
+  // Run over all API path strings and ensure each path is defined.
+  var failures = [];
+  getApiPaths().forEach(function(path) {
+    if (!testPath(path)) {
+      failures.push(path);
+    }
+  });
+
+  // Lack of failure implies success.
+  if (failures.length == 0) {
+    chrome.test.notifyPass();
+  } else {
+    console.log("failures on:\n" + failures.join("\n") +
+        "\n\n\n>>> See comment in stubs_apitest.cc for a " +
+        "hint about fixing this failure.\n\n");
+    chrome.test.notifyFail("failed");
+  }
+}
+
+chrome.app.runtime.onLaunched.addListener(function() {
+  doTest();
+});