Issue 28466. Include ErrorProcessor(s) into the AnalysisOptions signature.

pkg/analyzer/lib/source/error_processor.dart

 // Copyright (c) 2015, 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.
 
 library analyzer.source.error_processor;
 
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/error/codes.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/utilities_general.dart';
@@ skipping 66 matching lines @@
 
   /// Create an error processor that assigns errors with this [code] the
   /// given [severity].
   ///
   /// If [severity] is `null`, matching errors will be filtered.
   ErrorProcessor(this.code, [this.severity]);
 
   /// Create an error processor that ignores the given error by [code].
   factory ErrorProcessor.ignore(String code) => new ErrorProcessor(code);
 
+  /// The string that unique describes the processor.
+  String get description => '$code -> ${severity?.name}';
+
   /// Check if this processor applies to the given [error].
   bool appliesTo(AnalysisError error) => code == error.errorCode.name;
 
   /// Return an error processor associated in the [analysisOptions] for the
   /// given [error], or `null` if none is found.
   static ErrorProcessor getProcessor(
       AnalysisOptions analysisOptions, AnalysisError error) {
     if (analysisOptions == null) {
       return null;
     }
@@ skipping 13 matching lines @@
 
 /// In strong mode, this upgrades static type warnings to errors.
 class _StrongModeTypeErrorProcessor implements ErrorProcessor {
   static final instance = new _StrongModeTypeErrorProcessor();
 
   // TODO(rnystrom): As far as I know, this is only used to implement
   // appliesTo(). Consider making it private in ErrorProcessor if possible.
   String get code => throw new UnsupportedError(
       "_StrongModeTypeErrorProcessor is not specific to an error code.");
 
+  @override
+  String get description => 'allStrongWarnings -> ERROR';
+
   /// In strong mode, type warnings are upgraded to errors.
   ErrorSeverity get severity => ErrorSeverity.ERROR;
 
   /// Check if this processor applies to the given [error].
   bool appliesTo(AnalysisError error) {
     ErrorCode errorCode = error.errorCode;
     if (errorCode is StaticTypeWarningCode) {
       return true;
     }
     if (errorCode is StaticWarningCode) {
       return errorCode.isStrongModeError;
     }
     return false;
   }
 }