First implementation of chrome.platformKeys.

chrome/renderer/resources/extensions/platform_keys_custom_bindings.js

+// Copyright 2015 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.
+
+// Custom binding for the platformKeys API.
+
+var binding = require('binding').Binding.create('platformKeys');
+var SubtleCrypto = require('platformKeys.SubtleCrypto').SubtleCrypto;
+var internalAPI = require('platformKeys.internalAPI');
+
+binding.registerCustomHook(function(api) {
+  var apiFunctions = api.apiFunctions;
+  var subtleCrypto = new SubtleCrypto('' /* tokenId */);
+
+  apiFunctions.setHandleRequest(
+      'selectClientCertificates', function(details, callback) {
+        internalAPI.selectClientCertificates(details, callback);
+      });
+
+  apiFunctions.setHandleRequest(
+      'subtleCrypto', function() { return subtleCrypto });
+});
+
+exports.binding = binding.generate();