Remove dart:platform library.

tests/lib/lib.status

 # 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.
 
 [ $csp ]
 mirrors/delegate_test: RuntimeError # Issue 13864
 
 [ $compiler == dart2js ]
 async/schedule_microtask3_test: RuntimeError # _enqueueImmediate runs after Timer. http://dartbug.com/9002
 async/schedule_microtask6_test: RuntimeError # global error handling is not supported. http://dartbug.com/5958
@@ skipping 112 matching lines @@
 
 
 [ $compiler == dart2js && $browser ]
 async/timer_not_available_test: Fail, OK # only meant to test when there is no way to
                                          # implement timer (currently only in d8)
 
 [ $compiler == dart2dart ]
 mirrors/*: Skip # http://dartbug.com/11511
 async/schedule_microtask6_test: Fail             # Issue 10957 - may be related to issue 10910
 async/schedule_microtask3_test: RuntimeError # Issue 13719: Please triage this failure.
-platform/package_root_test: Fail # Issue 14451
-platform/script_test: Fail # Issue 14451
-platform/isolate_test: Fail # Issue 14451
-
 
 [ $compiler == dart2dart && $minified ]
 json/json_test: Fail                            # Issue 10961
 
 [ $compiler == dart2js && $minified ]
 mirrors/typedef_test/01: Fail # http://dartbug.com/6490
 
 [ $runtime == ff ]
 # FF setTimeout can fire early: https://bugzilla.mozilla.org/show_bug.cgi?id=291386
 async/multiple_timer_test: Pass, Fail
@@ skipping 36 matching lines @@
 mirrors/generic_f_bounded_test/01: RuntimeError # Issue 14000
 mirrors/symbol_validation_test: RuntimeError # Issue 13596
 
 async/timer_not_available_test: SkipByDesign # only meant to test when there is no way to implement timer (currently only in d8)
 
 [ $compiler == none && ( $runtime == drt || $runtime == dartium ) ]
 mirrors/immutable_collections_test: Fail # Issue 11857, Issue 14321
 mirrors/library_uri_io_test: Skip # Not intended for drt as it uses dart:io.
 mirrors/local_isolate_test: Skip # http://dartbug.com/12188
 async/schedule_microtask6_test: Fail # Issue 10910
-platform/isolate_test: Skip # Issue 14444
 
 [ $compiler == none && $runtime == drt && $mode == debug ]
 mirrors/hierarchy_invariants_test: Pass, Slow # Issue 14449
 
 [ $compiler == none && $runtime == drt && $system == windows ]
 async/multiple_timer_test: Fail, Pass # See Issue 10982
 async/timer_test: Fail, Pass # See Issue 10982
 
 [ $arch == simmips || $arch == mips ]
 convert/chunked_conversion_utf88_test: Pass, Slow # Issue 12025.
 convert/streamed_conversion_json_utf8_decode_test: Pass, Slow
 
 [ $arch == simarm ]
 convert/chunked_conversion_utf88_test: Pass, Slow # Issue 12644.
 convert/utf85_test: Pass, Slow # Issue 12644.
 
 [ $compiler == none && $runtime == dartium ]
 async/schedule_microtask5_test: Pass, Timeout # Issue 13719: Please triage this failure.
 async/timer_cancel2_test: Pass, Timeout # Issue 13719: Please triage this failure.
 
 [ $compiler == none && ($runtime == drt || $runtime == dartium) ]
 # Issue 13921: spawnFunction is not allowed on Dartium's DOM thread.
 async/timer_isolate_test: Fail
 
-[ $compiler == none && ($runtime == drt || $runtime == dartium) && $system == windows ]
-platform/uri_test: Fail # Issue 14504
-
 [ ($compiler != none && $runtime != none) || ($compiler == none && ($runtime != dartium && $runtime != drt)) ]
 async/schedule_microtask_test: Fail # Issue 9001, Issue 9002
 
 [ $compiler == dartanalyzer || $compiler == dart2analyzer ]
 async/future_test: StaticWarning
 async/future_value_chain4_test: StaticWarning
 async/schedule_microtask3_test: StaticWarning
 async/stream_controller_async_test: StaticWarning
 async/stream_controller_test: StaticWarning
 async/stream_event_transformed_test: StaticWarning
@@ skipping 20 matching lines @@
 mirrors/type_variable_owner_test: StaticWarning # Issue 14524
 mirrors/typedef_test: StaticWarning # Issue 14524
 mirrors/typedef_metadata_test: StaticWarning # Issue 14524
 mirrors/typevariable_mirror_metadata_test: StaticWarning # Issue 14524
 
 mirrors/fake_function_without_call_test: StaticWarning, OK # Implements Function without defining call.
 mirrors/find_in_context_fake_function_test: StaticWarning, OK # Implements Function without defining call.
 mirrors/immutable_collections_test: StaticWarning, OK # Expect failure for any type of Iterable.
 mirrors/inference_and_no_such_method_test: StaticWarning, OK # Expect to trigger noSuchMethod.
 mirrors/library_metadata2_test/01: StaticWarning, OK # Compile-time or run-time