Implement DownloadFile::Rename() for posix. Downloads work on linux!

base/file_util_posix.cc

Index: base/file_util_posix.cc
===================================================================
--- base/file_util_posix.cc	(revision 11648)
+++ base/file_util_posix.cc	(working copy)
@@ -107,8 +107,14 @@
 }
 
 bool Move(const FilePath& from_path, const FilePath& to_path) {
-  return (rename(from_path.value().c_str(),
-                 to_path.value().c_str()) == 0);
+  if (rename(from_path.value().c_str(), to_path.value().c_str()) == 0)
+    return true;
+
+  if (!CopyDirectory(from_path, to_path, true))
+    return false;
+
+  Delete(from_path, true);
+  return true;
 }
 
 bool CopyDirectory(const FilePath& from_path,