Cache HttpRequest in test.

dart/tests/try/web/web_compiler_test_case.dart

 // Copyright (c) 2014, 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.
 
 // Helpers for writing compiler tests running in browser.
 library trydart.web_compiler_test_case;
 
 import 'dart:async' show
     EventSink,
     Future;
@@ skipping 63 matching lines @@
   final String source;
 
   final Uri mainUri;
 
   final Uri libraryRoot;
 
   final Uri packageRoot;
 
   final Map<Uri, Future> cachedSources = new Map<Uri, Future>();
 
+  static final Map<String, Future> cachedRequests = new Map<String, Future>();
+
   WebInputProvider(
       this.source, this.mainUri, this.libraryRoot, this.packageRoot);
 
   Future call(Uri uri) {
     return cachedSources.putIfAbsent(uri, () {
       if (uri == mainUri) return new Future.value(source);
       if (uri.scheme == WEB_SCHEME) {
-        return HttpRequest.getString('/root_dart${uri.path}');
+        return cachedHttpRequest('/root_dart${uri.path}');
       } else {
-        return HttpRequest.getString('$uri');
+        return cachedHttpRequest('$uri');
       }
     });
   }
+
+  static Future cachedHttpRequest(String uri) {
+    return cachedRequests.putIfAbsent(uri, () => HttpRequest.getString(uri));
+  }
 }
 
 /// Output provider which collect output in [output].
 class OutputProvider {
   final Map<String, String> output = new Map<String, String>();
 
   EventSink<String> call(String name, String extension) {
     return new StringEventSink((String data) {
       output['$name.$extension'] = data;
     });
@@ skipping 19 matching lines @@
     throw 'addError($errorEvent, $stackTrace)';
   }
 
   void close() {
     if (data != null) {
       onClose(data.join());
       data = null;
     }
   }
 }