Add observatory_pub_packages snapshot to third_party

observatory_pub_packages/path/src/internal_style.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 path.internal_style;
+
+import 'context.dart';
+import 'style.dart';
+
+/// The internal interface for the [Style] type.
+///
+/// Users should be able to pass around instances of [Style] like an enum, but
+/// the members that [Context] uses should be hidden from them. Those members
+/// are defined on this class instead.
+abstract class InternalStyle extends Style {
+  /// The default path separator for this style.
+  ///
+  /// On POSIX, this is `/`. On Windows, it's `\`.
+  String get separator;
+
+  /// Returns whether [path] contains a separator.
+  bool containsSeparator(String path);
+
+  /// Returns whether [codeUnit] is the character code of a separator.
+  bool isSeparator(int codeUnit);
+
+  /// Returns whether this path component needs a separator after it.
+  ///
+  /// Windows and POSIX styles just need separators when the previous component
+  /// doesn't already end in a separator, but the URL always needs to place a
+  /// separator between the root and the first component, even if the root
+  /// already ends in a separator character. For example, to join "file://" and
+  /// "usr", an additional "/" is needed (making "file:///usr").
+  bool needsSeparator(String path);
+
+  /// Gets the root prefix of [path] if path is absolute. If [path] is relative,
+  /// returns `null`.
+  String getRoot(String path);
+
+  /// Gets the root prefix of [path] if it's root-relative.
+  ///
+  /// If [path] is relative or absolute and not root-relative, returns `null`.
+  String getRelativeRoot(String path);
+
+  /// Returns the path represented by [uri] in this style.
+  String pathFromUri(Uri uri);
+
+  /// Returns the URI that represents the relative path made of [parts].
+  Uri relativePathToUri(String path) =>
+      new Uri(pathSegments: context.split(path));
+
+  /// Returns the URI that represents [path], which is assumed to be absolute.
+  Uri absolutePathToUri(String path);
+}