Add patch file support to the analyzer task model.

pkg/analyzer/lib/src/task/dart.dart

Index: pkg/analyzer/lib/src/task/dart.dart
diff --git a/pkg/analyzer/lib/src/task/dart.dart b/pkg/analyzer/lib/src/task/dart.dart
index 56595c47e6ad7cf9cdef8a04f76406609c94de50..dd78ea0b132b5cfa968acad73646315cea198a45 100644
--- a/pkg/analyzer/lib/src/task/dart.dart
+++ b/pkg/analyzer/lib/src/task/dart.dart
@@ -23,6 +23,7 @@ import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/dart/resolver/inheritance_manager.dart';
 import 'package:analyzer/src/dart/scanner/reader.dart';
 import 'package:analyzer/src/dart/scanner/scanner.dart';
+import 'package:analyzer/src/dart/sdk/patch.dart';
 import 'package:analyzer/src/error/codes.dart';
 import 'package:analyzer/src/error/pending_error.dart';
 import 'package:analyzer/src/generated/constant.dart';
@@ -4024,6 +4025,11 @@ class ParseDartTask extends SourceBasedAnalysisTask {
     CompilationUnit unit = parser.parseCompilationUnit(tokenStream);
     unit.lineInfo = lineInfo;
 
+    if (options.patchPlatform != 0 && _source.uri.scheme == 'dart') {
+      new SdkPatcher().patch(context.sourceFactory.dartSdk,
+          options.patchPlatform, errorListener, _source, unit);
+    }
+
     bool hasNonPartOfDirective = false;
     bool hasPartOfDirective = false;
     HashSet<Source> explicitlyImportedSourceSet = new HashSet<Source>();