Practically remove boot.js, adds the initialization from the Dart side of

pkg/polymer/lib/src/build/polyfill_injector.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * Final phase of the polymer transformation: includes any additional polyfills
  * that may needed by the deployed app.
  */
 library polymer.src.build.polyfill_injector;
 
@@ skipping 43 matching lines @@
           dartScriptTags = true;
         }
       }
 
       if (!dartScriptTags) {
         // This HTML has no Dart code, there is nothing to do here.
         transform.addOutput(transform.primaryInput);
         return;
       }
 
-      if (!jsInteropFound) {
-        // JS interop code is required for Polymer CSS shimming.
+      _addScript(urlSegment) {
         document.body.nodes.insert(0, parseFragment(
-            '<script src="packages/browser/interop.js"></script>\n'));
+              '<script src="packages/$urlSegment"></script>\n'));
       }
 
+      // JS interop code is required for Polymer CSS shimming.
+      if (!jsInteropFound) _addScript('browser/interop.js');
       if (!customElementFound) {
-        document.body.nodes.insert(0, parseFragment(
-            '<script src="packages/custom_element/custom-elements.debug.js">'
-            '</script>\n'));
+        _addScript('custom_element/custom-elements.debug.js');
       }
 
-      if (!shadowDomFound) {
-        // Insert at the beginning (this polyfill needs to run as early as
-        // possible).
-        // TODO(jmesserly): this is .debug to workaround issue 13046.
-        document.body.nodes.insert(0, parseFragment(
-            '<script src="packages/shadow_dom/shadow_dom.debug.js"></script>\n'));
-      }
+      // This polyfill needs to be the first one on the body
+      // TODO(jmesserly): this is .debug to workaround issue 13046.
+      if (!shadowDomFound) _addScript('shadow_dom/shadow_dom.debug.js');

[Jennifer Messerly, 2013/10/17 02:04:35]

if you want to fix: this can be .min now, 13046 is fixed.

actually, we probably want to tie this to the "Pub build" settings ... if
dart2js is building minified we should include minified polyfills, else debug
polyfills. can we fix now, or should I open a bug to track this issue?

[Siggi Cherem (dart-lang), 2013/10/17 02:37:40]

:-) funny I thought about fixing this too, but decided to wait. I just have a
feeling this might trigger more failures in the bots and prefer to do it
separately.

I like your idea to do it more sensitive (only when --minify is on)

Filed:
https://code.google.com/p/dart/issues/detail?id=14161

 
       transform.addOutput(
           new Asset.fromString(transform.primaryInput.id, document.outerHtml));
     });
   }
 }
 
 final _shadowDomJS = new RegExp(r'shadow_dom\..*\.js', caseSensitive: false);
 final _customElementJS = new RegExp(r'custom-elements\..*\.js',
     caseSensitive: false);