Clarify in dev_compiler docs the reason for the angular whitelist hack

pkg/dev_compiler/lib/src/compiler/code_generator.dart

 // Copyright (c) 2015, 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.
 
 import 'dart:collection' show HashMap, HashSet;
 import 'dart:math' show min, max;
 
 import 'package:analyzer/analyzer.dart' hide ConstantEvaluator;
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 5854 matching lines @@
 
   JS.Statement _callHelperStatement(String code, args) {
     if (args is List) {
       args.insert(0, _runtimeModule);
     } else {
       args = [_runtimeModule, args];
     }
     return js.statement('#.$code', args);
   }
 
+  // TODO(kevmoo): https://github.com/dart-lang/sdk/issues/27255
+  // TODO(kevmoo): Remove once pkg/angular2 has moved to the new compiler
+  //               See https://github.com/dart-lang/angular2/issues/48
+  /// Temporary workaround *cough* total hack *cough*.
+  ///
   /// Maps whitelisted files to a list of whitelisted methods
   /// within the file.
   ///
   /// If the value is null, the entire file is whitelisted.
   ///
-  // TODO(jmesserly): why is this here, and what can we do to remove it?
-  //
-  // Hard coded lists are completely unnecessary -- if a feature is needed,
-  // metadata, type system features, or command line options are the right way
-  // to express it.
-  //
-  // As it is this is completely unsound and unmaintainable.
-  static Map<String, List<String>> _uncheckedWhitelist = {
-    'dom_renderer.dart': ['moveNodesAfterSibling'],
-    'template_ref.dart': ['createEmbeddedView'],
-    'ng_class.dart': ['_applyIterableChanges'],
-    'ng_for.dart': ['_bulkRemove', '_bulkInsert'],
-    'view_container_ref.dart': ['createEmbeddedView'],
+  static const Map<String, List<String>> _uncheckedWhitelist = const {
+    'dom_renderer.dart': const ['moveNodesAfterSibling'],
+    'template_ref.dart': const ['createEmbeddedView'],
+    'ng_class.dart': const ['_applyIterableChanges'],
+    'ng_for.dart': const ['_bulkRemove', '_bulkInsert'],
+    'view_container_ref.dart': const ['createEmbeddedView'],
     'default_iterable_differ.dart': null,
   };
 
   static Set<String> _uncheckedWhitelistCalls = new Set()
     ..add('ng_zone_impl.dart')
     ..add('stack_zone_specification.dart')
     ..add('view_manager.dart')
     ..add('view.dart');
 
   bool _inWhitelistCode(AstNode node, {isCall: false}) {
@@ skipping 136 matching lines @@
   if (targetIdentifier.staticElement is! PrefixElement) return false;
   var prefix = targetIdentifier.staticElement as PrefixElement;
 
   // The library the prefix is referring to must come from a deferred import.
   var containingLibrary = resolutionMap
       .elementDeclaredByCompilationUnit(target.root as CompilationUnit)
       .library;
   var imports = containingLibrary.getImportsWithPrefix(prefix);
   return imports.length == 1 && imports[0].isDeferred;
 }