Extract DiagnosticReporter implementation from Compiler.

pkg/compiler/lib/src/mirrors/dart2js_library_mirror.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.
 
 part of dart2js.mirrors;
 
 class Dart2JsLibraryMirror
     extends Dart2JsElementMirror
     with ObjectMirrorMixin, ContainerMixin
     implements LibrarySourceMirror {
@@ skipping 108 matching lines @@
   final Dart2JsLibraryMirror _targetLibrary;
   List<CombinatorMirror> _combinators;
 
   Dart2JsLibraryDependencyMirror(this._node,
                                  this._sourceLibrary,
                                  this._targetLibrary);
 
   SourceLocation get location {
     return new Dart2JsSourceLocation(
       _sourceLibrary._element.entryCompilationUnit.script,
-      _sourceLibrary.mirrorSystem.compiler.spanFromNode(_node));
+      _sourceLibrary.mirrorSystem.compiler.reporter.spanFromSpannable(_node));
   }
 
   List<CombinatorMirror> get combinators {
     if (_combinators == null) {
       _combinators = <CombinatorMirror>[];
       if (_node.combinators != null) {
         for (Combinator combinator in _node.combinators.nodes) {
           List<String> identifiers = <String>[];
           for (Identifier identifier in combinator.identifiers.nodes) {
             identifiers.add(identifier.source);
@@ skipping 108 matching lines @@
   int get offset => _span.begin;
 
   int get length => _span.end - _span.begin;
 
   String get text => _script.text.substring(_span.begin, _span.end);
 
   Uri get sourceUri => _script.resourceUri;
 
   String get sourceText => _script.text;
 }