Don't report redundant type errors in strong mode.

pkg/analyzer/test/source/error_processor_test.dart

Index: pkg/analyzer/test/source/error_processor_test.dart
diff --git a/pkg/analyzer/test/source/error_processor_test.dart b/pkg/analyzer/test/source/error_processor_test.dart
index 968d6195f77ef1fc5c3e6a20a24425f83f9039c4..864bbf84f57115c85c250dbae2af06195f8e8ed4 100644
--- a/pkg/analyzer/test/source/error_processor_test.dart
+++ b/pkg/analyzer/test/source/error_processor_test.dart
@@ -45,7 +45,7 @@ main() {
     context = new TestContext();
   });
 
-  group('ErrorProcessorTest', () {
+  group('ErrorProcessor', () {
     test('configureOptions', () {
       configureOptions('''
 analyzer:
@@ -60,9 +60,17 @@ analyzer:
       expect(getProcessor(unused_local_variable), isNull);
       expect(getProcessor(use_of_void_result), isNull);
     });
+
+    test('upgrades static type warnings to errors in strong mode', () {
+      configureOptions('''
+analyzer:
+  strong-mode: true
+''');
+      expect(getProcessor(invalid_assignment).severity, ErrorSeverity.ERROR);
+    });
   });
 
-  group('ErrorConfigTest', () {
+  group('ErrorConfig', () {
     var config = '''
 analyzer:
   errors: