watch the registration queue and print if it has no progress

pkg/polymer/CHANGELOG.md

Index: pkg/polymer/CHANGELOG.md
diff --git a/pkg/polymer/CHANGELOG.md b/pkg/polymer/CHANGELOG.md
index 375b5d5b9fd7ef1941ddbb4fc74133315b739758..a21d7ca6fc2e4a73f86fd8b9002ab01d1085502f 100644
--- a/pkg/polymer/CHANGELOG.md
+++ b/pkg/polymer/CHANGELOG.md
@@ -5,6 +5,8 @@
   * Added Polymer.waitingFor method. This returns a list of all polymer-element
     declarations that are still waiting for their class definitions to be
     loaded.
+  * Add runtime checking of the waitingFor queue and print to the console if a
+    deadlock situation is suspected to help diagnose the white screen of death.
   * Added injectBoundHTML instance method. This can be used to dynamically
     inject html that is bound to your current element into a target element.