Rip out dart:io from pkg/http wherever possible.

pkg/http/lib/src/client.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 client;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:typed_data';
 
@@ skipping 74 matching lines @@
   /// Sends an HTTP DELETE request with the given headers to the given URL,
   /// which can be a [Uri] or a [String].
   ///
   /// For more fine-grained control over the request, use [send] instead.
   Future<Response> delete(url, {Map<String, String> headers});
 
   /// Sends an HTTP GET request with the given headers to the given URL, which
   /// can be a [Uri] or a [String], and returns a Future that completes to the
   /// body of the response as a String.
   ///
-  /// The Future will emit an [HttpException] if the response doesn't have a
+  /// The Future will emit a [ClientException] if the response doesn't have a
   /// success status code.
   ///
   /// For more fine-grained control over the request and response, use [send] or
   /// [get] instead.
   Future<String> read(url, {Map<String, String> headers});
 
   /// Sends an HTTP GET request with the given headers to the given URL, which
   /// can be a [Uri] or a [String], and returns a Future that completes to the
   /// body of the response as a list of bytes.
   ///
-  /// The Future will emit an [HttpException] if the response doesn't have a
+  /// The Future will emit a [ClientException] if the response doesn't have a
   /// success status code.
   ///
   /// For more fine-grained control over the request and response, use [send] or
   /// [get] instead.
   Future<Uint8List> readBytes(url, {Map<String, String> headers});
 
   /// Sends an HTTP request and asynchronously returns the response.
   Future<StreamedResponse> send(BaseRequest request);
 
   /// Closes the client and cleans up any resources associated with it. It's
   /// important to close each client when it's done being used; failing to do so
   /// can cause the Dart process to hang.
   void close();
 }