Try running ie10 in a new window instead of an iframe.

tools/testing/dart/browser_controller.dart

 // Copyright (c) 2013, 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 browser;
 
 import "dart:async";
 import "dart:convert" show LineSplitter, UTF8;
 import "dart:core";
 import "dart:io";
 
@@ skipping 73 matching lines @@
       throw "Non supported browser";
     }
     browser._binary = executablePath;
     return browser;
   }
 
   static const List<String> SUPPORTED_BROWSERS =
     const ['safari', 'ff', 'firefox', 'chrome', 'ie9', 'ie10',
            'ie11', 'dartium'];
 
-  static const List<String> BROWSERS_WITH_WINDOW_SUPPORT = const ['ie11'];
+  static const List<String> BROWSERS_WITH_WINDOW_SUPPORT =
+      const ['ie11', 'ie10'];
 
   // TODO(kustermann): add standard support for chrome on android
   static bool supportedBrowser(String name) {
     return SUPPORTED_BROWSERS.contains(name);
   }
 
   void _logEvent(String event) {
     String toLog = "$this ($id) - $event \n";
     if (debugPrint) print("usageLog: $toLog");
     if (logger != null) logger(toLog);
@@ skipping 1496 matching lines @@
     Dart test driver, number of tests: <div id="number"></div><br>
     Currently executing: <div id="currently_executing"></div><br>
     Unhandled error: <div id="unhandled_error"></div>
     <iframe id="embedded_iframe"></iframe>
   </body>
 </html>
 """;
     return driverContent;
   }
 }