From 7d0485b18da07ea208dbac874dad03c2f4816401 Mon Sep 17 00:00:00 2001
From: Steven Orvell <sorvell@google.com>
Date: Tue, 5 Jan 2016 14:35:21 -0800
Subject: [PATCH] Fixes #3270.

---
 src/lib/base.html            |  1 -
 test/unit/bind-elements.html | 20 ++++++++++++++++++++
 test/unit/bind.html          |  9 +++++++++
 3 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/src/lib/base.html b/src/lib/base.html
index 920b71d559..10f6b4d491 100644
--- a/src/lib/base.html
+++ b/src/lib/base.html
@@ -33,7 +33,6 @@
 
     createdCallback: function() {
       Polymer.telemetry.instanceCount++;
-      this.isAttached = false;
       this.root = this;
       this._doBehavior('created'); // abstract
       this._initFeatures(); // abstract
diff --git a/test/unit/bind-elements.html b/test/unit/bind-elements.html
index 3b47ab58ef..e18ab7af69 100644
--- a/test/unit/bind-elements.html
+++ b/test/unit/bind-elements.html
@@ -468,3 +468,23 @@
     <input id="input" value$="{{inputValue}}">
   </template>
 </dom-module>
+
+
+<dom-module id="x-bind-is-attached">
+  <template>
+    <div id="check">{{isAttached}}</div>
+  </template>
+  <script>
+    Polymer({
+      is: 'x-bind-is-attached',
+      properties: {
+        isAttached: {
+          observer: '_isAttachedChanged'
+        }
+      },
+      _isAttachedChanged: function() {}
+    });
+  </script>
+</dom-module>
+
+<s
\ No newline at end of file
diff --git a/test/unit/bind.html b/test/unit/bind.html
index bec2bf9a1e..7be58b8913 100644
--- a/test/unit/bind.html
+++ b/test/unit/bind.html
@@ -719,6 +719,15 @@
     assert.equal(el.$.binding.textContent, 'binding');
   });
 
+  test('bind to isAttached', function() {
+    var el = document.createElement('x-bind-is-attached');
+    sinon.spy(el, '_isAttachedChanged');
+    document.body.appendChild(el);
+    Polymer.dom.flush();
+    assert.equal(el.$.check.textContent, 'true');
+    assert.isTrue(el._isAttachedChanged.calledOnce);
+    document.body.removeChild(el);
+  });
 });
 
 suite('compound binding / string interpolation', function() {