Provide a dart2js implementation of dart:debugger

sdk/lib/_internal/libraries.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.
 
 library libraries;
 
 /**
  * A bit flag used by [LibraryInfo] indicating that a library is used by dart2js
  */
 const int DART2JS_PLATFORM = 1;
@@ skipping 38 matching lines @@
       maturity: Maturity.STABLE,
       dart2jsPatchPath: "_internal/compiler/js_lib/convert_patch.dart"),
 
   "core": const LibraryInfo(
       "core/core.dart",
       maturity: Maturity.STABLE,
       dart2jsPatchPath: "_internal/compiler/js_lib/core_patch.dart"),
 
   "debugger": const LibraryInfo(
       "debugger/debugger.dart",
-      maturity: Maturity.UNSTABLE),
+      maturity: Maturity.UNSTABLE,
+      dart2jsPatchPath: "_internal/compiler/js_lib/debugger_patch.dart"),
 
   "html": const LibraryInfo(
       "html/dartium/html_dartium.dart",
       category: "Client",
       maturity: Maturity.WEB_STABLE,
       dart2jsPath: "html/dart2js/html_dart2js.dart"),
 
   "html_common": const LibraryInfo(
       "html/html_common/html_common.dart",
       category: "Client",
@@ skipping 260 matching lines @@
   static const Maturity STABLE = const Maturity(4, "Stable",
     "The library is stable. API backwards-compatibility is guaranteed.\n"
     "However implementation details might change.");
 
   static const Maturity LOCKED = const Maturity(5, "Locked",
     "This library will not change except when serious bugs are encountered.");
 
   static const Maturity UNSPECIFIED = const Maturity(-1, "Unspecified",
     "The maturity for this library has not been specified.");
 }