Fix http requests and the crash dump RPC

runtime/observatory/lib/src/elements/logging.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 logging_page;
 
 import 'dart:async';
 import 'dart:html';
 import 'observatory_element.dart';
 import 'package:logging/logging.dart';
@@ skipping 138 matching lines @@
     if (container == null) {
       return;
     }
     // Adjust scroll so that the bottom of the content is visible.
     container.scrollTop = container.scrollHeight - container.clientHeight;
   }
 
   _flushPendingLogs() {
     DivElement logContainer = shadowRoot.querySelector(_kLogSelector);
     bool autoScroll = _isScrolledToBottom(logContainer);
-    var lastElement;
     for (var logRecord in pendingLogRecords) {
-      lastElement = _renderAppend(logRecord);
+      _renderAppend(logRecord);
     }
     if (autoScroll) {
       _scrollToBottom(logContainer);
     }
     pendingLogRecords.clear();
   }
 
   _onEvent(ServiceEvent event) {
     assert(event.kind == Isolate.kLoggingStream);
     _append(event.logRecord);
@@ skipping 21 matching lines @@
 
   @observable Isolate isolate;
   @observable String severityLevel;
   int _severityLevelValue = 0;
   int _maxLevelLabelLength = 0;
   Future<StreamSubscription> _loggingSubscriptionFuture;
   StreamSubscription _resizeSubscription;
   final List<Map> logRecords = new List<Map>();
   final List<Map> pendingLogRecords = new List<Map>();
 }