Mark supportsPointConversions deprecated and always true rather than testing DOMPoint

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.
 
 interactive_test: Skip # Must be run manually.
 cross_frame_test: Skip # Test reloads itself. Issue 18558
 
 [ $compiler == none && ($runtime == dartium || $runtime == drt) ]
 
 js_array_test: Skip # Dartium JSInterop failure
@@ skipping 136 matching lines @@
 text_event_test: RuntimeError # Issue 23437
 transition_event_test/functional: Skip # Times out. Issue 22167
 request_animation_frame_test: Skip # Times out. Issue 22167
 
 [$runtime == ie10 ]
 # IE10 Feature support statuses-
 # All changes should be accompanied by platform support annotation changes.
 audiobuffersourcenode_test/supported: Fail
 audiocontext_test/supported: Fail
 crypto_test/supported: Fail
-css_test/supportsPointConversions: Fail
 document_test/supports_cssCanvasContext: Fail
 element_types_test/supported_content: Fail
 element_types_test/supported_details: Fail
 element_types_test/supported_keygen: Fail
 element_types_test/supported_meter: Fail
 element_types_test/supported_output: Fail
 element_types_test/supported_shadow: Fail
 element_types_test/supported_template: Fail
 fileapi_test/supported: Fail
 history_test/supported_HashChangeEvent: Fail
@@ skipping 22 matching lines @@
 websql_test/supported: Fail
 xhr_test/json: Fail # IE10 returns string, not JSON object
 xhr_test/supported_overrideMimeType: Fail
 xsltprocessor_test/supported: Fail
 worker_test/functional: Fail # IE uses incorrect security context for Blob URIs.
 transferables_test: Fail # Issue 9846
 
 [ $compiler == dart2js && $minified ]
 canvas_pixel_array_type_alias_test/types2_runtimeTypeName: Fail, OK # Issue 12605
 
-[ $compiler == dart2js && $runtime == chrome ]
-css_test/supportsPointConversions: Fail # Issues 21710
-css_test/functional: Fail # Issues 21710
-
 [ $runtime == ie11 ]
 custom/document_register_type_extensions_test/single-parameter: Fail # Issue 13193.
 canvasrenderingcontext2d_test/arc: Pass, Fail # Pixel unexpected value. Please triage this failure.
 worker_test/functional: Pass, Fail # Issues 20659.
 transferables_test: Pass, Fail # Issues 20659.
 
 # IE11 Feature support statuses-
 # These results not yet noted in platform support annotations.
 # All changes should be accompanied by platform support annotation changes.
 audiobuffersourcenode_test/supported: Fail
 audiocontext_test/supported: Fail
 crypto_test/supported: Fail
-css_test/supportsPointConversions: Fail
 document_test/supports_cssCanvasContext: Fail
 element_types_test/supported_content: Fail
 element_types_test/supported_details: Fail
 element_types_test/supported_keygen: Fail
 element_types_test/supported_meter: Fail
 element_types_test/supported_output: Fail
 element_types_test/supported_shadow: Fail
 element_types_test/supported_template: Fail
 fileapi_test/supported: Fail
 history_test/supported_HashChangeEvent: Fail
@@ skipping 99 matching lines @@
 keyboard_event_test: Fail # Issue: 7413
 serialized_script_value_test: Fail
 typed_arrays_arraybuffer_test: Fail
 url_test: Fail
 
 # Opera Feature support statuses-
 # All changes should be accompanied by platform support annotation changes.
 audiobuffersourcenode_test/supported: Fail
 audiocontext_test/supported: Fail
 crypto_test/supported: Fail
-css_test/supportsPointConversions: Fail
 document_test/supports_cssCanvasContext: Fail
 element_types_test/supported_template: Fail
 indexeddb_1_test/supported: Fail
 indexeddb_1_test/supportsDatabaseNames: Fail
 mutationobserver_test/supported: Fail
 performance_api_test/supported: Fail
 speechrecognition_test/supported: Fail
 websql_test/supported: Fail
 
 [  $compiler == dart2js && $runtime == ff ]
@@ skipping 76 matching lines @@
 queryall_test: fail
 track_element_constructor_test: StaticWarning
 transferables_test: StaticWarning
 typed_arrays_range_checks_test: StaticWarning
 typing_test: StaticWarning
 webgl_1_test: StaticWarning
 window_nosuchmethod_test: StaticWarning
 
 [ $compiler == dart2js && $cps_ir ]
 resource_http_test: Crash # (await for(var b in r.openRead()){bytes.addAll(b);}): await for