Rename Unforgeable to LegacyUnforgeable.

This CL rename Web IDL |Unforgeable| to |LegacyUnforgeable| to make its
usage more clear.

Bug: 1072773
Change-Id: I534ee3610f5e866ed4aa14ffcd6b6f6a90d648ae
diff --git a/common/stringifiers.js b/common/stringifiers.js
index 4ef7a1b..18de6c8 100644
--- a/common/stringifiers.js
+++ b/common/stringifiers.js
@@ -2,7 +2,7 @@
  * Runs tests for <http://heycam.github.io/webidl/#es-stringifier>.
  * @param {Object} aObject - object to test
  * @param {string} aAttribute - IDL attribute name that is annotated with `stringifier`
- * @param {boolean} aIsUnforgeable - whether the IDL attribute is `[Unforgeable]`
+ * @param {boolean} aIsUnforgeable - whether the IDL attribute is `[LegacyUnforgeable]`
  */
 function test_stringifier_attribute(aObject, aAttribute, aIsUnforgeable) {
   // Step 1.
diff --git a/html/browsers/the-window-object/proxy-getOwnPropertyDescriptor.html b/html/browsers/the-window-object/proxy-getOwnPropertyDescriptor.html
index c3db82f..88032fa 100644
--- a/html/browsers/the-window-object/proxy-getOwnPropertyDescriptor.html
+++ b/html/browsers/the-window-object/proxy-getOwnPropertyDescriptor.html
@@ -52,7 +52,7 @@
     Object.getOwnPropertyDescriptor(window, 'document')
   );
   assert_equals(trapCalls, 1);
-}, 'Window target, forwarding trap, [Unforgeable] "document" attribute');
+}, 'Window target, forwarding trap, [LegacyUnforgeable] "document" attribute');
 
 test(() => {
   const trapResult = {get() {}, set(_val) {}, enumerable: false, configurable: true};
@@ -80,7 +80,7 @@
     Object.getOwnPropertyDescriptor(document, 'location')
   );
   assert_equals(trapCalls, 1);
-}, 'Document target, forwarding trap, [Unforgeable] "location" attribute');
+}, 'Document target, forwarding trap, [LegacyUnforgeable] "location" attribute');
 
 test(() => {
   const trapResult = {value: 4, writable: false, enumerable: true, configurable: true};
@@ -104,7 +104,7 @@
   assert_equals(location.hash, '#new');
   assert_true(descriptor.enumerable);
   assert_false(descriptor.configurable);
-}, 'Location target, no trap, [Unforgeable] "hash" attribute');
+}, 'Location target, no trap, [LegacyUnforgeable] "hash" attribute');
 
 test(() => {
   let trapCalls = 0;
@@ -120,7 +120,7 @@
     Object.getOwnPropertyDescriptor(location, 'reload')
   );
   assert_equals(trapCalls, 1);
-}, 'Location proxy target, forwarding trap, [Unforgeable] "reload" method');
+}, 'Location proxy target, forwarding trap, [LegacyUnforgeable] "reload" method');
 </script>
 </body>
 </html>