Remove _HttpUtils from dart:io.

tests/standalone/standalone.status

 # 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.
 
 # WARNING:
 # Tests using the multitest feature where failure is expected should *also* be
 # listed in tests/lib/analyzer/analyze_tests.status without the "standalone"
 # prefix.
 
 package/invalid_uri_test: Fail, OK # Fails intentionally
@@ skipping 49 matching lines @@
 
 # test issue https://code.google.com/p/dart/issues/detail?id=11518
 io/file_constructor_test: fail
 
 # The dart:io library is created at build time from separate files, and
 # there is no language-spec compatible way to run unit tests on the private
 # members and methods of dart:io.
 # Dart analyzer spots the misuse of 'part' directives in these unit tests.
 io/http_headers_test: Skip
 io/http_cookie_date_test: Skip
-io/url_encoding_test: Skip
 io/http_parser_test: Skip
 io/web_socket_protocol_processor_test: Skip
 
 # This is runtime test.
 io/process_exit_negative_test: Skip
 
 [ $compiler == dart2analyzer ]
 53bit_overflow_literal_test/01: fail, ok
 
 # test issue https://code.google.com/p/dart/issues/detail?id=11518
 io/file_constructor_test: fail
 
 # The dart:io library is created at build time from separate files, and
 # there is no language-spec compatible way to run unit tests on the private
 # members and methods of dart:io.
 # Dart analyzer spots the misuse of 'part' directives in these unit tests.
 io/http_headers_test: Skip
 io/http_cookie_date_test: Skip
-io/url_encoding_test: Skip
 io/http_parser_test: Skip
 io/web_socket_protocol_processor_test: Skip
 
 # This is runtime test.
 io/process_exit_negative_test: Skip
 
 [ $compiler == dart2js ]
 number_identity_test: Skip # Bigints and int/double diff. not supported.
 typed_data_test: Skip # dart:typed_data support needed.
 bytedata_test: Skip # dart:typed_data support needed.
 typed_data_view_test: Skip # dart:typed_data support needed.
 typed_data_isolate_test: Skip # dart:typed_data support needed.
 typed_array_int64_uint64_test: Skip # dart:typed_data on dart2js does not support 64-bit ints.
 float_array_test: Skip # dart:typed_data support needed.
 int_array_test: Skip  # dart:typed_data support needed.
 io/web_socket_protocol_processor_test: Skip  # Importing code with external keyword
-io/url_encoding_test: Skip  # Importing code with external keyword
 int_array_load_elimination_test: Skip  # This is a VM test
 medium_integer_test: Fail, OK # Test fails with JS number semantics: issue 1533.
 io/process_exit_negative_test: Fail, OK # relies on a static error that is a warning now.
 package/package_isolate_test: Skip # spawnUri does not work in dart2js. See issue 3051
 debugger/*: Skip # Do not run standalone vm debugger tests with dart2js.
 left_shift_bit_and_op_test: Skip # Integers exceed dart2js precision.
 pow_test: Skip # Precision > 53 bits.
 http_launch_test: Skip
 53bit_overflow_test: Skip
 53bit_overflow_literal_test: Skip
@@ skipping 27 matching lines @@
 
 [ $arch == simarm ]
 out_of_memory_test: Skip # passes on Mac, crashes on Linux
 
 [ $arch == mips ]
 *: Skip
 
 [ $arch == simmips ]
 io/file_fuzz_test: Pass, Timeout
 out_of_memory_test: Skip # passes on Mac, crashes on Linux