Convert string16 to base::string16 in content.

content/browser/renderer_host/render_message_filter.cc

Index: content/browser/renderer_host/render_message_filter.cc
diff --git a/content/browser/renderer_host/render_message_filter.cc b/content/browser/renderer_host/render_message_filter.cc
index 3aca534e48ef8993f4383e116a243508e0c8eb23..10a3901eeff5b89379f634a74fee10a2d95401d1 100644
--- a/content/browser/renderer_host/render_message_filter.cc
+++ b/content/browser/renderer_host/render_message_filter.cc
@@ -843,7 +843,7 @@ void RenderMessageFilter::OnGetMonitorColorProfile(std::vector<char>* profile) {
 void RenderMessageFilter::OnDownloadUrl(const IPC::Message& message,
                                         const GURL& url,
                                         const Referrer& referrer,
-                                        const string16& suggested_name) {
+                                        const base::string16& suggested_name) {
   scoped_ptr<DownloadSaveInfo> save_info(new DownloadSaveInfo());
   save_info->suggested_name = suggested_name;
   scoped_ptr<net::URLRequest> request(
@@ -1112,7 +1112,7 @@ void RenderMessageFilter::OnDidLose3DContext(
 
 #if defined(OS_WIN)
 void RenderMessageFilter::OnPreCacheFontCharacters(const LOGFONT& font,
-                                                   const string16& str) {
+                                                   const base::string16& str) {
   // First, comments from FontCacheDispatcher::OnPreCacheFont do apply here too.
   // Except that for True Type fonts,
   // GetTextMetrics will not load the font in memory.