Always return computed errors, even for not added files.

pkg/analyzer/lib/src/dart/analysis/driver.dart

 // Copyright (c) 2016, 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.
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:typed_data';
 
 import 'package:analyzer/context/declared_variables.dart';
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 768 matching lines @@
             // Store the result into the cache.
             bytes = _serializeResolvedUnit(resolvedUnit, errors);
             _byteStore.put(key, bytes);
           }
 
           // Return the result, full or partial.
           _logger.writeln('Computed new analysis result.');
           AnalysisResult result = _getAnalysisResultFromBytes(
               file, signature, bytes,
               content: withUnit ? file.content : null,
-              withErrors: _fileTracker.addedFiles.contains(path),
               resolvedUnit: withUnit ? resolvedUnit : null);
           if (withUnit && _priorityFiles.contains(path)) {
             _priorityResults[path] = result;
           }
           return result;
         } finally {
           libraryContext.dispose();
         }
       } catch (exception, stackTrace) {
         String contextKey =
@@ skipping 70 matching lines @@
       _salt[i + 1] = crossContextOptions[i];
     }
   }
 
   /**
    * Load the [AnalysisResult] for the given [file] from the [bytes]. Set
    * optional [content] and [resolvedUnit].
    */
   AnalysisResult _getAnalysisResultFromBytes(
       FileState file, String signature, List<int> bytes,
-      {String content, bool withErrors: true, CompilationUnit resolvedUnit}) {
+      {String content, CompilationUnit resolvedUnit}) {
     var unit = new AnalysisDriverResolvedUnit.fromBuffer(bytes);
-    List<AnalysisError> errors = withErrors
-        ? _getErrorsFromSerialized(file, unit.errors)
-        : const <AnalysisError>[];
+    List<AnalysisError> errors = _getErrorsFromSerialized(file, unit.errors);
     return new AnalysisResult(
         this,
         _sourceFactory,
         file.path,
         file.uri,
         file.exists,
         content,
         file.contentHash,
         file.lineInfo,
         signature,
@@ skipping 1009 matching lines @@
           libraryDeclarations.add(new TopLevelDeclarationInSource(
               file.source, declaration, isExported));
         }
       }
     }
 
     // We're not done yet.
     return false;
   }
 }