Change other usages of .size() to .empty() when applicable.

chrome/browser/debugger/extension_ports_remote_service.cc

 // Copyright (c) 2010 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.
 
 // Implementation of the ExtensionPortsRemoteService.
 
 // Inspired significantly from debugger_remote_service
 // and ../automation/extension_port_container.
 
 #include "chrome/browser/debugger/extension_ports_remote_service.h"
@@ skipping 156 matching lines @@
   if (!service_) {
     // This happens if we failed to obtain an ExtensionMessageService
     // during initialization.
     NOTREACHED();
     response.SetInteger(kResultKey, RESULT_NO_SERVICE);
     SendResponse(response, message.tool(), message.destination());
     return;
   }
 
   int destination = -1;
-  if (destinationString.size() != 0)
+  if (!destinationString.empty())
     base::StringToInt(destinationString, &destination);
 
   if (command == kConnect) {
     if (destination != -1)  // destination should be empty for this command.
       response.SetInteger(kResultKey, RESULT_UNKNOWN_COMMAND);
     else
       ConnectCommand(content, &response);
   } else if (command == kDisconnect) {
     if (destination == -1)  // Destination required for this command.
       response.SetInteger(kResultKey, RESULT_UNKNOWN_COMMAND);
@@ skipping 191 matching lines @@
     VLOG(1) << "unknown port: " << port_id;
     response->SetInteger(kResultKey, RESULT_UNKNOWN_PORT);
     return;
   }
   // Post the message through the ExtensionMessageService.
   DCHECK(service_);
   service_->PostMessageFromRenderer(port_id, message);
   // Confirm to the external client that we sent its message.
   response->SetInteger(kResultKey, RESULT_OK);
 }