Use a transformer to initialize custom elements and call initMethod. This is the

pkg/polymer/CHANGELOG.md

 # changelog
 
 This file contains highlights of what changes on each version of the polymer
 package. We will also note important changes to the polyfill packages if they
 impact polymer: custom_element, html_import, observe, shadow_dom,
 and template_binding.
 
+#### Pub version 0.10.0-dev
+  * Deploy step removes use of mirrors to initialize polymer elements. Mirrors
+    are still used for @published and for polymer-expressions.
+    **breaking change**: @initMethod and @CustomTag are only supported on
+    public classes/methods.
+
+#### Pub version 0.9.5
+  * Improvements on how to handle cross-package HTML imports.
+
 #### Pub version 0.9.4
   * Removes unused dependency on csslib.
 
 #### Pub version 0.9.3+3
   * Removes workaround now that mirrors implement a missing feature. Requires
     SDK >= 1.1.0-dev.5.0.
 
 #### Pub version 0.9.3+2
   * Fix rare canonicalization bug
     [15694](https://code.google.com/p/dart/issues/detail?id=15694)
 
 #### Pub version 0.9.3+1
   * Fix type error in runner.dart
     [15649](https://code.google.com/p/dart/issues/detail?id=15649).
 
 #### Pub version 0.9.3
   * pub-build now runs the linter automatically
 
 #### Pub version 0.9.2+4
   * fix linter on SVG and MathML tags with XML namespaces
 
 #### Pub version 0.9.2+3
   * fix [15574](https://code.google.com/p/dart/issues/detail?id=15574),
     event bindings in dart2js, by working around issue
     [15573](https://code.google.com/p/dart/issues/detail?id=15573)
 
 #### Pub version 0.9.2+2
   * fix enteredView in dart2js, by using custom_element >= 0.9.1+1