Disable auto "debugger" call for tests

pkg/dev_compiler/test/browser/language_tests.js

 // Copyright (c) 2015, 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.
 
 define(['dart_sdk', 'async_helper', 'expect', 'unittest', 'is', 'require'],
       function(dart_sdk, async_helper, expect, unittest, is, require) {
   'use strict';
 
   async_helper = async_helper.async_helper;
   let minitest = expect.minitest;
 
+  dart_sdk.dart.trapRuntimeErrors(false);
   dart_sdk._isolate_helper.startRootIsolate(function() {}, []);
   let html_config = unittest.html_config;
   // Test attributes are a list of strings, or a string for a single
   // attribute. Valid attributes are:
   //
   //   'pass' - test passes (default)
   //   'skip' - don't run the test
   //   'fail' - test fails
   //   'timeout' - test times out
   //   'slow' - use 5s timeout instead of default 2s.
@@ skipping 820 matching lines @@
 
     for (let action of unittest_tests) {
       try {
         action();
       } catch (e) {
         console.error("Caught error tying to setup test:", e);
       }
     }
   });
 });