Lazy load chrome.* APIs

chrome/renderer/resources/extensions/bluetooth_custom_bindings.js

Index: chrome/renderer/resources/extensions/bluetooth_custom_bindings.js
diff --git a/chrome/renderer/resources/extensions/bluetooth_custom_bindings.js b/chrome/renderer/resources/extensions/bluetooth_custom_bindings.js
index e1f75f5d78ac9ff69d574696852ab3b6e6308462..273a094932499f99250e1181d5c58efa775f65d5 100644
--- a/chrome/renderer/resources/extensions/bluetooth_custom_bindings.js
+++ b/chrome/renderer/resources/extensions/bluetooth_custom_bindings.js
@@ -2,24 +2,27 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Custom bindings for the Bluetooth API.
+// Custom binding for the Bluetooth API.
+
+var binding = require('binding').Binding.create('bluetooth');
 
 var chromeHidden = requireNative('chrome_hidden').GetChromeHidden();
+var chrome = requireNative('chrome').GetChrome();
 var sendRequest = require('sendRequest').sendRequest;
 var lastError = require('lastError');
 
-// Use custom bindings to create an undocumented event listener that will
+// Use custom binding to create an undocumented event listener that will
 // receive events about device discovery and call the event listener that was
 // provided with the request to begin discovery.
-chromeHidden.registerCustomHook('bluetooth', function(api) {
+binding.registerCustomHook(function(api) {
   var apiFunctions = api.apiFunctions;
 
   chromeHidden.bluetooth = {};
 
-  function callCallbackIfPresent(args) {
-    if (typeof(args[args.length-1]) == "function") {
-      args[args.length-1]();
-    }
+  function callCallbackIfPresent(args, error) {
+    var callback = args[args.length - 1];
+    if (typeof(callback) == "function")
+      lastError.run(error, callback);
   }
 
   chromeHidden.bluetooth.deviceDiscoveredHandler = null;
@@ -35,8 +38,7 @@ chromeHidden.registerCustomHook('bluetooth', function(api) {
         var args = arguments;
         if (args.length > 0 && args[0] && args[0].deviceCallback) {
           if (chromeHidden.bluetooth.deviceDiscoveredHandler != null) {
-            lastError.set("Concurrent discovery is not allowed.");
-            callCallbackIfPresent(args);
+            callCallbackIfPresent(args, "Concurrent discovery is not allowed.");
             return;
           }
 
@@ -49,8 +51,9 @@ chromeHidden.registerCustomHook('bluetooth', function(api) {
                       this.definition.parameters,
                       {customCallback:this.customCallback});
         } else {
-          lastError.set("deviceCallback is required in the options object");
-          callCallbackIfPresent(args);
+          callCallbackIfPresent(
+              args, "deviceCallback is required in the options object");
+          return;
         }
       });
   apiFunctions.setCustomCallback('startDiscovery',
@@ -154,3 +157,5 @@ chromeHidden.registerCustomHook('bluetooth', function(api) {
         return args;
       });
 });
+
+exports.binding = binding.generate();