First pass at cleaning up html lib warnings from the analyzer.

tools/dom/src/native_DOMImplementation.dart

 // Copyright (c) 2012, 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.
 
 part of html;
 
 class _ConsoleVariables {
   Map<String, Object> _data = new Map<String, Object>();
 
   /**
@@ skipping 388 matching lines @@
     LibraryMirror lib = cls.owner;
     String libName = lib.uri.toString();
     return libName.startsWith('dart:');
   }
 
   static void register(Document document, String tag, Type type,
       String extendsTagName) {
     // TODO(vsm): Move these checks into native code.
     ClassMirror cls = reflectClass(type);
     if (_isBuiltinType(cls)) {
-      throw new UnsupportedError("Invalid custom element from $libName.");
+      throw new UnsupportedError("Invalid custom element from ${cls.owner.uri}.");
     }
     var className = MirrorSystem.getName(cls.simpleName);
     var createdConstructor = cls.declarations[new Symbol('$className.created')];
     if (createdConstructor == null ||
         createdConstructor is! MethodMirror ||
         !createdConstructor.isConstructor) {
       throw new UnsupportedError(
           'Class is missing constructor $className.created');
     }
 
@@ skipping 86 matching lines @@
   void operator []=(String key, String value) native "DOMStringMap_setItem_Callback";
   String putIfAbsent(String key, String ifAbsent()) => Maps.putIfAbsent(this, key, ifAbsent);
   String remove(String key) native "DOMStringMap_remove_Callback";
   void clear() => Maps.clear(this);
   void forEach(void f(String key, String value)) => Maps.forEach(this, f);
   Iterable<String> get keys native "DOMStringMap_getKeys_Callback";
   Iterable<String> get values => Maps.getValues(this);
   int get length => Maps.length(this);
   bool get isEmpty => Maps.isEmpty(this);
   bool get isNotEmpty => Maps.isNotEmpty(this);
+  void addAll(Map<String, String> other) {
+    other.forEach((key, value) => this[key] = value);
+  }
 }
 
 final _printClosure = window.console.log;
 final _pureIsolatePrintClosure = (s) {
   throw new UnimplementedError("Printing from a background isolate "
                                "is not supported in the browser");
 };
 
 final _forwardingPrintClosure = _Utils.forwardingPrint;
 
@@ skipping 86 matching lines @@
   _scheduleImmediateHelper._schedule(callback);
 };
 
 get _pureIsolateScheduleImmediateClosure => ((void callback()) =>
   throw new UnimplementedError("scheduleMicrotask in background isolates "
                                "are not supported in the browser"));
 
 void _initializeCustomElement(Element e) {
   _Utils.initializeCustomElement(e);
 }