Remove support for the old Span classes from source_maps.

pkg/source_maps/lib/src/span_wrapper.dart

-// Copyright (c) 2014, 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 source_maps.span_wrapper;
-
-import 'package:source_span/source_span.dart' as source_span;
-
-import '../span.dart';
-
-/// A wrapper that exposes a [source_span.SourceSpan] as a [Span].
-class SpanWrapper extends Span {
-  final source_span.SourceSpan _inner;
-
-  String get text => _inner.text;
-
-  SpanWrapper(source_span.SourceSpan inner, bool isIdentifier)
-      : _inner = inner,
-        super(
-            new LocationWrapper(inner.start),
-            new LocationWrapper(inner.end),
-            isIdentifier);
-
-  static Span wrap(span, [bool isIdentifier = false]) {
-    if (span is Span) return span;
-    return new SpanWrapper(span, isIdentifier);
-  }
-}
-
-/// A wrapper that exposes a [source_span.SourceLocation] as a [Location].
-class LocationWrapper extends Location {
-  final source_span.SourceLocation _inner;
-
-  String get sourceUrl => _inner.sourceUrl.toString();
-  int get line => _inner.line;
-  int get column => _inner.column;
-
-  LocationWrapper(source_span.SourceLocation inner)
-      : _inner = inner,
-        super(inner.offset);
-
-  static Location wrap(location) {
-    if (location is Location) return location;
-    return new LocationWrapper(location);
-  }
-}
-
-/// A wrapper that exposes a [source_span.SourceFile] as a [SourceFile].
-class SourceFileWrapper implements SourceFile {
-  final source_span.SourceFile _inner;
-
-  // These are necessary to avoid analyzer warnings;
-  final _lineStarts = null;
-  final _decodedChars = null;
-
-  String get url => _inner.url.toString();
-
-  SourceFileWrapper(this._inner);
-
-  static SourceFile wrap(sourceFile) {
-    if (sourceFile is SourceFile) return sourceFile;
-    return new SourceFileWrapper(sourceFile);
-  }
-
-  Span span(int start, [int end, bool isIdentifier = false]) {
-    if (end == null) end = start;
-    return new SpanWrapper(_inner.span(start, end), isIdentifier);
-  }
-
-  Location location(int offset) => new LocationWrapper(_inner.location(offset));
-
-  int getLine(int offset) => _inner.getLine(offset);
-
-  int getColumn(int line, int offset) => _inner.getColumn(offset, line: line);
-
-  int getOffset(int line, int column) => _inner.getOffset(line, column);
-
-  String getText(int start, [int end]) => _inner.getText(start, end);
-
-  String getLocationMessage(String message, int start, int end,
-      {bool useColors: false, String color}) {
-    return span(start, end).getLocationMessage(message,
-        useColors: useColors, color: color);
-  }
-}