[net] Cleanup filename_util and make it portable.

content/child/web_url_loader_impl.cc

Index: content/child/web_url_loader_impl.cc
diff --git a/content/child/web_url_loader_impl.cc b/content/child/web_url_loader_impl.cc
index 1f852bdc03385c5917f7e853707b637c9db4d2a4..d5387c79c3e1e4319bc213b8d690fbb9361a950f 100644
--- a/content/child/web_url_loader_impl.cc
+++ b/content/child/web_url_loader_impl.cc
@@ -1069,12 +1069,11 @@ void WebURLLoaderImpl::PopulateURLResponse(const GURL& url,
   std::string value;
   headers->EnumerateHeader(NULL, "content-disposition", &value);
   response->setSuggestedFileName(
-      net::GetSuggestedFilename(url,
-                                value,
-                                std::string(),  // referrer_charset
-                                std::string(),  // suggested_name
-                                std::string(),  // mime_type
-                                std::string()));  // default_name
+      net::GenerateFileName(url, value,
+                            std::string(),  // referrer_charset
+                            std::string(),  // suggested_name
+                            std::string(),  // mime_type
+                            std::string()).AsUTF16Unsafe());  // default_name
 
   Time time_val;
   if (headers->GetLastModifiedValue(&time_val))