[net] Cleanup filename_util and make it portable.

content/browser/web_contents/web_drag_source_mac.mm

 // 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.
 
 #import "content/browser/web_contents/web_drag_source_mac.h"
 
 #include <sys/param.h>
 
 #include "base/bind.h"
 #include "base/files/file.h"
@@ skipping 51 matching lines @@
 // Returns a filename appropriate for the drop data
 // TODO(viettrungluu): Refactor to make it common across platforms,
 // and move it somewhere sensible.
 base::FilePath GetFileNameFromDragData(const DropData& drop_data) {
   base::FilePath file_name(
       FilePathFromFilename(drop_data.file_description_filename));
 
   // Images without ALT text will only have a file extension so we need to
   // synthesize one from the provided extension and URL.
   if (file_name.empty()) {
-    // Retrieve the name from the URL.
-    base::string16 suggested_filename =
-        net::GetSuggestedFilename(drop_data.url, "", "", "", "", "");
-    const std::string extension = file_name.Extension();
-    file_name = FilePathFromFilename(suggested_filename);
-    file_name = file_name.ReplaceExtension(extension);
+    file_name =
+        net::GenerateFileName(drop_data.url, std::string(), std::string(),
+                              std::string(), std::string(), std::string());
   }
 
   return file_name;
 }
 
 // This helper's sole task is to write out data for a promised file; the caller
 // is responsible for opening the file. It takes the drop data and an open file
 // stream.
 void PromiseWriterHelper(const DropData& drop_data,
                          base::File file) {
@@ skipping 369 matching lines @@
 - (NSImage*)dragImage {
   if (dragImage_)
     return dragImage_;
 
   // Default to returning a generic image.
   return content::GetContentClient()->GetNativeImageNamed(
       IDR_DEFAULT_FAVICON).ToNSImage();
 }
 
 @end  // @implementation WebDragSource (Private)