Add "platforms" key in IDL schema compiler.

chrome/renderer/resources/extensions/binding.js

 // Copyright (c) 2012 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 Event = require('event_bindings').Event;
 var forEach = require('utils').forEach;
 var GetAvailability = requireNative('v8_context').GetAvailability;
 var logActivity = requireNative('activityLogger');
 var logging = requireNative('logging');
 var process = requireNative('process');
@@ skipping 96 matching lines @@
 
   for (var i = 0; i < platforms.length; i++) {
     if ($RegExp.test(platforms[i][0], navigator.appVersion)) {
       return platforms[i][1];
     }
   }
   return "unknown";
 }
 
 function isPlatformSupported(schemaNode, platform) {
-  return !schemaNode.platforms ||
+  return !schemaNode.platforms || schemaNode.platforms.length == 0 ||

[not at google - send to devlin, 2013/10/25 17:00:08]

if something specificies "platforms: []" then it should be an error, not work
for all platforms.

[Haojian Wu, 2013/10/26 03:15:51]

Done.

       schemaNode.platforms.indexOf(platform) > -1;
 }
 
 function isManifestVersionSupported(schemaNode, manifestVersion) {
   return !schemaNode.maximumManifestVersion ||
       manifestVersion <= schemaNode.maximumManifestVersion;
 }
 
 function isSchemaNodeSupported(schemaNode, platform, manifestVersion) {
   return isPlatformSupported(schemaNode, platform) &&
@@ skipping 297 matching lines @@
                         availability.message);
       return;
     }
 
     this.runHooks_(mod);
     return mod;
   }
 };
 
 exports.Binding = Binding;