Update test expectations to reflect errors that are now warning.

pkg/dev_compiler/tool/sdk_expected_errors.txt

Index: pkg/dev_compiler/tool/sdk_expected_errors.txt
diff --git a/pkg/dev_compiler/tool/sdk_expected_errors.txt b/pkg/dev_compiler/tool/sdk_expected_errors.txt
index f4c6ea419d6002a30eede3bd85047c589d2e5546..befa245834be24b7005a19dc39ee5341b4dadc19 100644
--- a/pkg/dev_compiler/tool/sdk_expected_errors.txt
+++ b/pkg/dev_compiler/tool/sdk_expected_errors.txt
@@ -55,7 +55,6 @@ Consider passing explicit type argument(s) to the generic.
 [error] Invalid override. The type of 'ZLibEncoder.startChunkedConversion' ('(Sink<List<int>>) → ByteConversionSink') isn't a subtype of 'ChunkedConverter<List<int>, List<int>, List<int>, List<int>>.startChunkedConversion' ('(dynamic) → dynamic'). (dart:io/data_transformer.dart, line 388, col 3)
 [error] The argument type '(RandomAccessFile) → Future<RandomAccessFile>' can't be assigned to the parameter type '(RandomAccessFile) → FutureOr<File>'. (dart:io/file_impl.dart, line 202, col 30)
 [error] The return type 'Future<Object>' isn't a 'FutureOr<File>', as defined by the method ''. (dart:io/file_impl.dart, line 591, col 14)
-[error] The type of '_startTime' can't be inferred because of the use of the instance getter 'millisecondsSinceEpoch'. (dart:io/io_resource_info.dart, line 14, col 48)
 [error] Undefined name 'lineMode'. (dart:io/stdio.dart, line 57, col 10)
 [error] The name 'echoMode=' is already defined. (dart:io/stdio.dart, line 122, col 12)
 [error] The name 'lineMode=' is already defined. (dart:io/stdio.dart, line 143, col 12)
@@ -100,6 +99,7 @@ Consider passing explicit type argument(s) to the generic.
 [warning] The final variables 'form', 'labels' and '5' more must be initialized. (dart:html, line 33132, col 3)
 [warning] The final variables 'readyState' and 'track' must be initialized. (dart:html, line 34173, col 3)
 [warning] The final variables 'decodedFrameCount', 'droppedFrameCount' and '2' more must be initialized. (dart:html, line 34889, col 3)
+[warning] The final variable '_isTranslatable' must be initialized. (dart:io/stdio.dart, line 327, col 3)
 [warning] The final variables 'href' and 'target' must be initialized. (dart:svg, line 56, col 3)
 [warning] The final variables 'requiredExtensions', 'requiredFeatures' and '2' more must be initialized. (dart:svg, line 512, col 3)
 [warning] The final variables 'cx', 'cy' and '1' more must be initialized. (dart:svg, line 587, col 3)