Removing setImmediate and hiding WindowTimers interface (take 2)

tests/html/html.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.
 
 async_window_test: Skip #TODO(gram): investigating
 event_test: Skip  # Issue 1996
 interactive_test: Skip # Must be run manually.
 
 [ $compiler == dart2js && $browser ]
 element_offset_test/offset: Pass, Fail # Issue 13296
@@ skipping 91 matching lines @@
 [ $compiler == none && ($runtime == drt || $runtime == dartium) && $mode == debug]
 websql_test: Fail, Pass # Issue 4941: stderr contains a backtrace.
 
 [ $compiler == dart2js && $runtime == drt && $system == macos]
 audiobuffersourcenode_test: Pass, Fail
 
 [$runtime == ie10 ]
 dromaeo_smoke_test: Skip #TODO(efortuna): investigating.
 element_test/click: Fail                # IE does not support firing this event.
 history_test/history: Pass, Fail # issue 8183
-microtask_test: Fail, Pass # Appears to be flaky
 native_gc_test: Fail, Pass # BUG(7774): Untriaged.
 serialized_script_value_test: Fail
 storage_test: Fail, Pass
 transferables_test: Fail # Issue 9846
 websocket_test/websocket: Fail # TODO(efortuna): Issue 7875.
 canvasrenderingcontext2d_test/drawImage_video_element: Fail # IE does not support drawImage w/ video element
 canvasrenderingcontext2d_test/drawImage_video_element_dataUrl: Fail # IE does not support drawImage w/ video element
 worker_test/functional: Fail # IE uses incorrect security context for Blob URIs.
 custom/entered_left_view_test: Skip # Issue 13551 - IE is timing out
 
@@ skipping 47 matching lines @@
 [ $runtime == ie9 ]
 isolates_test: Timeout # Issue 13027
 blob_constructor_test: Fail
 custom/document_register_type_extensions_test/namespaces: Fail # Issue 13193
 document_test/document: Pass, Fail # BUG(9654) need per-instance patching
 dom_constructors_test: Fail
 dromaeo_smoke_test: Skip #TODO(efortuna): investigating.
 element_test/click: Fail                # IE does not support firing this event.
 form_element_test: Fail # Issue 4793.
 localstorage_test: Fail
-microtask_test: Pass, Fail # http://dartbug.com/8300
 postmessage_structured_test: Skip   # BUG(5685): times out.
 serialized_script_value_test: Fail
 url_test: Fail              # IE9 does not support createObjectURL (it is supported in IE10)
 canvasrenderingcontext2d_test/drawImage_video_element: Fail # IE does not support drawImage w/ video element
 canvasrenderingcontext2d_test/drawImage_video_element_dataUrl: Fail # IE does not support drawImage w/ video element
 canvasrenderingcontext2d_test/drawImage_image_element: Pass, Fail # Issue: 11416
 input_element_test/attributes: Fail # IE returns null while others ''
 xhr_cross_origin_test: Skip # Issue 12920
 xhr_test/json: Fail # IE9 returns null because of unsupported type
 
@@ skipping 216 matching lines @@
 wheelevent_test: Fail # http://dartbug.com/12958
 
 [ $compiler == none && $runtime == dartium ]
 async_test: Timeout # Issue 13719: Please triage this failure.
 dromaeo_smoke_test: Fail # Issue 13719: Please triage this failure.
 element_offset_test/offset: Fail # Issue 13719: Please triage this failure.
 touchevent_test/supported: Fail # Issue 13719: Please triage this failure.
 
 [ $compiler == dart2js ]
 custom/document_register_type_extensions_test/registration: Fail # Issue 14093