[Extensions] Finish freezing schema

extensions/renderer/resources/binding.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 Event = require('event_bindings').Event;
 var forEach = require('utils').forEach;
 // Note: Beware sneaky getters/setters when using GetAvailbility(). Use safe/raw
 // variables as arguments.
 var GetAvailability = requireNative('v8_context').GetAvailability;
 var exceptionHandler = require('uncaught_exception_handler');
@@ skipping 466 matching lines @@
         if (propertyName in m)
           return;  // TODO(kalman): be strict like functions/events somehow.
         if (!isSchemaNodeSupported(propertyDef, platform, manifestVersion))
           return;
         if (!GetAvailability(schema.namespace + "." +
               propertyName).is_available ||
             (checkUnprivileged && !isSchemaAccessAllowed(propertyDef))) {
           return;
         }
 
-        var value = propertyDef.value;
+        // |value| is eventually added to |m|, the exposed API. Make copies
+        // of everything from the schema. (The schema is also frozen, so as long
+        // as we don't make any modifications, shallow copies are fine.)
+        var value;
+        if ($Array.isArray(propertyDef.value))
+          value = $Array.slice(propertyDef.value);
+        else if (typeof propertyDef.value === 'object')
+          value = $Object.assign({}, propertyDef.value);
+        else
+          value = propertyDef.value;
+
         if (value) {
           // Values may just have raw types as defined in the JSON, such
           // as "WINDOW_ID_NONE": { "value": -1 }. We handle this here.
           // TODO(kalman): enforce that things with a "value" property can't
           // define their own types.
           var type = propertyDef.type || typeof(value);
           if (type === 'integer' || type === 'number') {
             value = parseInt(value);
           } else if (type === 'boolean') {
             value = value === 'true';
@@ skipping 57 matching lines @@
                     availability.message);
       return;
     }
 
     this.runHooks_(mod, schema);
     return mod;
   }
 };
 
 exports.$set('Binding', Binding);