Fix exitcode handling from analyzer running in nobatch mode.

tools/testing/dart/test_runner.dart

 // Copyright (c) 2012, 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.
 
 /**
  * Classes and methods for executing tests.
  *
  * This module includes:
  * - Managing parallel execution of tests, including timeout checks.
  * - Evaluating the output of each test as pass/fail/crash/timeout.
@@ skipping 947 matching lines @@
             break;
           }
         }
       }
       numStaticTypeAnnotations = optionsFromFile['numStaticTypeAnnotations'];
       numCompileTimeAnnotations = optionsFromFile['numCompileTimeAnnotations'];
       isStaticClean = optionsFromFile['isStaticClean'];
     }
 
     if (errors.length == 0) {
-      if (!hasFatalTypeErrors && exitCode != 0) {
+      // If the analyzer has warnings it will exit 1.
+      // We should reconsider how we do this once we have landed a dart
+      // only version of the analyzer for stable use (as in not run in batch
+      // mode).
+      if (!hasFatalTypeErrors && exitCode != 0 && staticWarnings.length == 0) {
         diagnostics.add("EXIT CODE MISMATCH: Expected error message:");
         diagnostics.add("  command[0]:${testCase.commands[0]}");
         diagnostics.add("  exitCode:${exitCode}");
         return true;
       }
     } else if (exitCode == 0) {
       diagnostics.add("EXIT CODE MISMATCH: Unexpected error message:");
       diagnostics.add("  errors[0]:${errors[0]}");
       diagnostics.add("  command[0]:${testCase.commands[0]}");
       diagnostics.add("  exitCode:${exitCode}");
@@ skipping 1088 matching lines @@
     }
   }
 
   void eventAllTestsDone() {
     for (var listener in _eventListener) {
       listener.allDone();
     }
     _allDone();
   }
 }