Coverity: Fix several pass-by-values.

content/browser/webui/web_ui_message_handler.cc

Index: content/browser/webui/web_ui_message_handler.cc
diff --git a/content/browser/webui/web_ui_message_handler.cc b/content/browser/webui/web_ui_message_handler.cc
index bf2d391003e941365eca02a9082c833711782dec..7e7e3eaf371612c283257c320060502479430026 100644
--- a/content/browser/webui/web_ui_message_handler.cc
+++ b/content/browser/webui/web_ui_message_handler.cc
@@ -14,21 +14,21 @@
 namespace content {
 
 void WebUIMessageHandler::SetURLAndTitle(DictionaryValue* dictionary,
-                                         string16 title,
+                                         const string16& title,
                                          const GURL& gurl) {
   dictionary->SetString("url", gurl.spec());
 
   bool using_url_as_the_title = false;
+  string16 title_to_set(title);
   if (title.empty()) {
     using_url_as_the_title = true;
-    title = UTF8ToUTF16(gurl.spec());
+    title_to_set = UTF8ToUTF16(gurl.spec());
   }
 
   // Since the title can contain BiDi text, we need to mark the text as either
   // RTL or LTR, depending on the characters in the string. If we use the URL
   // as the title, we mark the title as LTR since URLs are always treated as
   // left to right strings.
-  string16 title_to_set(title);
   if (base::i18n::IsRTL()) {
     if (using_url_as_the_title) {
       base::i18n::WrapStringWithLTRFormatting(&title_to_set);