Implement 'analysis.getErrors' for the new driver.

pkg/analysis_server/lib/src/protocol_server.dart

Index: pkg/analysis_server/lib/src/protocol_server.dart
diff --git a/pkg/analysis_server/lib/src/protocol_server.dart b/pkg/analysis_server/lib/src/protocol_server.dart
index 3b61ade76b0d7d0ea236cc86695e73d6f65ca6d0..596b8732cd7cc59db3ba5058622e192ce7da3125 100644
--- a/pkg/analysis_server/lib/src/protocol_server.dart
+++ b/pkg/analysis_server/lib/src/protocol_server.dart
@@ -30,12 +30,13 @@ export 'package:analysis_server/plugin/protocol/protocol_dart.dart';
  * errors.
  */
 List<AnalysisError> doAnalysisError_listFromEngine(
-    engine.AnalysisContext context,
+    engine.AnalysisOptions analysisOptions,
     engine.LineInfo lineInfo,
     List<engine.AnalysisError> errors) {
   List<AnalysisError> serverErrors = <AnalysisError>[];
   for (engine.AnalysisError error in errors) {
-    ErrorProcessor processor = ErrorProcessor.getProcessor(context, error);
+    ErrorProcessor processor =
+        ErrorProcessor.getProcessor(analysisOptions, error);
     if (processor != null) {
       engine.ErrorSeverity severity = processor.severity;
       // Errors with null severity are filtered out.