Make source maps work in the browser.

lib/src/runner/browser/server.dart

 // 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.
 
 library test.runner.browser.server;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
@@ skipping 311 matching lines @@
     });
   }
 
   /// Compile the test suite at [dartPath] to JavaScript.
   ///
   /// Once the suite has been compiled, it's added to [_jsHandler] so it can be
   /// served.
   Future _compileSuite(String dartPath) {
     return _compileFutures.putIfAbsent(dartPath, () async {
       var dir = new Directory(_compiledDir).createTempSync('test_').path;
-      var jsPath = p.join(dir, p.basename(dartPath) + ".js");
+      var jsPath = p.join(dir, p.basename(dartPath) + ".browser_test.dart.js");
 
       await _compilers.compile(dartPath, jsPath,
           packageRoot: _config.packageRoot);
       if (_closed) return;
 
       var jsUrl = p.toUri(p.relative(dartPath, from: _root)).path +
           '.browser_test.dart.js';
       _jsHandler.add(jsUrl, (request) {
         return new shelf.Response.ok(new File(jsPath).readAsStringSync(),
             headers: {'Content-Type': 'application/javascript'});
@@ skipping 63 matching lines @@
       await Future.wait(futures);
 
       if (_config.pubServeUrl == null) {
         new Directory(_compiledDir).deleteSync(recursive: true);
       } else {
         _http.close();
       }
     });
   }
 }