Update to use one less proxy per element

test/src/common/polymer_mixin_test.html

Index: test/src/common/polymer_mixin_test.html
diff --git a/test/src/common/polymer_mixin_test.html b/test/src/common/polymer_mixin_test.html
index fad5f51972fdb5635ae2ede44524fa4ace03c786..2a88fb928211beb1a44d5dae0b59a1a53ce5bc5f 100644
--- a/test/src/common/polymer_mixin_test.html
+++ b/test/src/common/polymer_mixin_test.html
@@ -19,6 +19,15 @@ BSD-style license that can be found in the LICENSE file.
           child
         </div>
       </div>
+      <!-- Makes sure that if a list is in a binding the updates don't happen twice -->

[Siggi Cherem (dart-lang), 2015/09/17 21:11:59]

is this a pitfall also in polymer.js or just for us? Do we need to document this
to warn our users?

[jakemac, 2015/09/23 17:37:08]

This is only for Polymer Dart elements. This is just ensuring that the bad
behavior doesn't happen, so as long as this test is passing there shouldn't be
any user facing issues.

[Siggi Cherem (dart-lang), 2015/09/24 20:23:07]

Oh - ok, maybe then change:

Makes sure that ...

=>

This test makes sure that ...

(I thought the "makes sure" was for the next line in some obscure way)

[jakemac, 2015/09/25 15:43:11]

Done.

+      <sub-element id="sub" my-ints="{{myInts}}" my-map="{{myMap}}"
+          my-model="{{myModel}}"></sub-element>
+    </template>
+  </dom-module>
+
+  <dom-module id="sub-element">
+    <template>
+      <span id="modelValue">{{myModel.value}}</span>
     </template>
   </dom-module>
 </body>