make ref private API

This patch is the first step towards making ref resolve the first time that an instance is produced, but allowing dynamic tracking of ref by all instances (including binding to ref).

R=arv
BUG=

Review URL: https://codereview.appspot.com/60640045

src/TemplateBinding.js

@@ -458,7 +458,7 @@
       if (bindingDelegate)
         delegate_ = this.newDelegate_(bindingDelegate);
 
-      var content = this.ref.content;
+      var content = this.ref_.content;
       var map = this.bindingMap_;
       if (!map || map.content !== content) {
         // TODO(rafaelw): Setup a MutationObserver on content to detect
@@ -565,15 +565,15 @@
       this.setDelegate_(this.newDelegate_(bindingDelegate));
     },
 
-    get ref() {
+    get ref_() {
       var ref = searchRefId(this, this.getAttribute('ref'));
       if (!ref)
         ref = this.instanceRef_;
 
       if (!ref)
         return this;
 
-      var nextRef = ref.ref;
+      var nextRef = ref.ref_;
       return nextRef ? nextRef : ref;
     }
   });

tests/tests.js

@@ -1452,8 +1452,6 @@ suite('Template Instantiation', function() {
     var t1 = div.firstChild;
     var t2 = div.childNodes[1];
 
-    assert.strictEqual(t1, t2.ref);
-
     var model = {name: 'Fry'};
     t2.model = model;
 
@@ -2040,7 +2038,6 @@ suite('Template Instantiation', function() {
       assert.strictEqual(2, select.childNodes.length);
       assert.strictEqual(1, select.selectedIndex);
       assert.strictEqual('TEMPLATE', select.childNodes[0].tagName);
-      assert.strictEqual('OPTGROUP', select.childNodes[0].ref.content.firstChild.tagName);
       var optgroup = select.childNodes[1];
       assert.strictEqual('TEMPLATE', optgroup.childNodes[0].tagName);
       assert.strictEqual('OPTION', optgroup.childNodes[1].tagName);
@@ -2669,7 +2666,6 @@ suite('Template Instantiation', function() {
     };
 
     var instance = outer.createInstance(model, delegate);
-    assert.strictEqual(instance.firstChild.ref, outer.content.firstChild);
     assert.strictEqual('bar:replaced',
                        instance.firstChild.nextSibling.textContent);
     unbindAll(instance);
@@ -3232,15 +3228,18 @@ suite('Binding Delegate API', function() {
     });
   });
 
-  test('issue-152', function() {
+  test('issue-152', function(done) {
     var div = createTestHtml(
-        '<template ref=notThere></template>');
+        '<template ref=notThere bind>XXX</template>');
 
     var template = div.firstChild;
-
-    // if a ref cannot be located, a template will continue to use itself
-    // as the source of template instances.
-    assert.strictEqual(template, template.ref);
+    template.model = {};
+    then(function() {
+      // if a ref cannot be located, a template will continue to use itself
+      // as the source of template instances.
+      assert.strictEqual('XXX', div.childNodes[1].textContent);
+      done();
+    })
   });
 });