Cleanup: Pass std::string as const reference from content/

content/browser/shared_worker/shared_worker_service_impl_unittest.cc

 // Copyright 2014 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 <map>
 #include <set>
 #include <vector>
 
 #include "base/atomic_sequence_num.h"
 #include "base/basictypes.h"
@@ skipping 266 matching lines @@
                      url,
                      name,
                      document_id,
                      render_frame_route_id,
                      &route_id_);
   }
   void SendQueueMessages() {
     EXPECT_TRUE(renderer_host_->OnMessageReceived(
         new MessagePortHostMsg_QueueMessages(remote_port_id_)));
   }
-  void SendPostMessage(std::string data) {
+  void SendPostMessage(const std::string& data) {
     const std::vector<TransferredMessagePort> empty_ports;
     EXPECT_TRUE(
         renderer_host_->OnMessageReceived(new MessagePortHostMsg_PostMessage(
             local_port_id_,
             MessagePortMessage(base::ASCIIToUTF16(data)), empty_ports)));
   }
   void SendConnect() {
     EXPECT_TRUE(
         renderer_host_->OnMessageReceived(new ViewHostMsg_ForwardToWorker(
             WorkerMsg_Connect(route_id_, remote_port_id_, MSG_ROUTING_NONE))));
@@ skipping 612 matching lines @@
                      kDocumentIDs[2],
                      kRenderFrameRouteIDs[2]);
   EXPECT_NE(MSG_ROUTING_NONE, connector2->route_id());
   EXPECT_EQ(0U, renderer_host2->QueuedMessageCount());
   RunAllPendingInMessageLoop();
   EXPECT_EQ(1U, renderer_host2->QueuedMessageCount());
   CheckViewMsgWorkerCreated(renderer_host2.get(), connector2.get());
 }
 
 }  // namespace content