Ensure tests have an active task runner

components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 128 matching lines @@
 
   void RunUntilIdle() {
     test_context_->RunUntilIdle();
   }
 
   net::MockClientSocketFactory* mock_socket_factory() {
     return &mock_socket_factory_;
   }
 
  private:
+  base::MessageLoopForIO message_loop_;
   net::TestURLRequestContext context_;
   net::MockClientSocketFactory mock_socket_factory_;
 
   scoped_ptr<DataReductionProxyTestContext> test_context_;
   scoped_ptr<DataReductionProxyRequestOptions> request_options_;
 };
 
 TEST_F(DataReductionProxyConfigServiceClientTest, TestConstructStaticResponse) {
   scoped_ptr<DataReductionProxyConfigServiceClient> config_client =
       BuildConfigClient();
@@ skipping 222 matching lines @@
   };
   net::StaticSocketDataProvider socket_data_provider(
       success_reads, arraysize(success_reads), nullptr, 0);
   mock_socket_factory()->AddSocketDataProvider(&socket_data_provider);
   config_client()->RetrieveConfig();
   RunUntilIdle();
   VerifyRemoteSuccess();
 }
 
 }  // namespace data_reduction_proxy