enterprise.platformKeys: Copy-on-read the 'algorithm' member of Key objects.

extensions/renderer/resources/utils.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 createClassWrapper = requireNative('utils').createClassWrapper;
 var schemaRegistry = requireNative('schema_registry');
 var CHECK = requireNative('logging').CHECK;
 var WARNING = requireNative('logging').WARNING;
 
 /**
@@ skipping 106 matching lines @@
         get: function() {
           return privates(this).impl[readonly];
         },
       });
     });
   }
 
   return publicClass;
 }
 
+/**
+ * Copies |value| recursively. |value| must not contain cyclic references.
+ * Copies only nested structures of non-object types (like number or string),
+ * Array, Uint8Array and the directly owned properties of objects (it ignores
+ * prototypes).

[not at google - send to devlin, 2014/06/19 00:12:42]

there's actually a really sneaky way you can implement this method I think: use
SerializedScriptValue, the utility that IndexedDB uses to serialize and
deserialize values. that should handle everything: cycles, exotic types like
uint8array...

see here:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

It seems as though this function could be:

function deepCopy(value) {
  return utilsNatives.DeepCopy(value);
}

with DeepCopy defined in utils_native_handler.cc:

void DeepCopy(v8::Arguments args) {
  args.SetResult(
      WebSerializedScriptValue::serialize(args[0]).deserialize());
}

[pneubeck (no reviews), 2014/06/19 16:09:41]

Done.

+ */
+function deepCopy(value) {
+  if (value === null)
+    return null;
+  if (typeof(value) !== 'object')
+    return value;
+
+  var copy = null;
+  if (Array.isArray(value) ) {
+    copy = new Array();
+    for (var i = 0; i < value.length; i++)
+      copy[i] = deepCopy(value[i]);
+  } else if (value.__proto__.constructor.name === 'Uint8Array') {

[not at google - send to devlin, 2014/06/19 00:12:42]

I don't think you need the __proto__ ? just value.constructor.name should be
fine, or is there some tricky thing that could happen?

+    copy = new Uint8Array(value.length);
+    for (var i = 0; i < value.length; i++)
+      copy[i] = value[i];
+  } else {
+    copy = new Object();
+    for (var key in value) {
+      if (!value.hasOwnProperty(key))
+        continue;
+      copy[key] = deepCopy(value[key]);

[not at google - send to devlin, 2014/06/19 00:12:42]

nit: I would invert the hasOwnProperty check to save 1 line :)

+    }
+  }
+  return copy;
+}
+
 exports.forEach = forEach;
 exports.loadTypeSchema = loadTypeSchema;
 exports.lookup = lookup;
 exports.expose = expose;
+exports.deepCopy = deepCopy;