Use const_iterator while iterating const std::set<>&

content/browser/tracing/tracing_ui.cc

 // Copyright (c) 2012 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 "content/browser/tracing/tracing_ui.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 504 matching lines @@
     std::set<std::string> ret;
     OnKnownCategoriesCollected(ret);
   }
 }
 
 void TracingMessageHandler::OnKnownCategoriesCollected(
     const std::set<std::string>& known_categories) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   scoped_ptr<base::ListValue> categories(new base::ListValue());
-  for (std::set<std::string>::iterator iter = known_categories.begin();
+  for (std::set<std::string>::const_iterator iter = known_categories.begin();
        iter != known_categories.end();
        ++iter) {
     categories->AppendString(*iter);
   }
 
   web_ui()->CallJavascriptFunction(
       "tracingController.onKnownCategoriesCollected", *categories);
 }
 
 }  // namespace
 
 
 ////////////////////////////////////////////////////////////////////////////////
 //
 // TracingUI
 //
 ////////////////////////////////////////////////////////////////////////////////
 
 TracingUI::TracingUI(WebUI* web_ui) : WebUIController(web_ui) {
   web_ui->AddMessageHandler(new TracingMessageHandler());
 
   // Set up the chrome://tracing/ source.
   BrowserContext* browser_context =
       web_ui->GetWebContents()->GetBrowserContext();
   WebUIDataSource::Add(browser_context, CreateTracingHTMLSource());
 }
 
 }  // namespace content