Move logging.h's definitions of operator<< into namespace std.

base/files/file_path_watcher_win.cc

Index: base/files/file_path_watcher_win.cc
diff --git a/base/files/file_path_watcher_win.cc b/base/files/file_path_watcher_win.cc
index 6c10c12d313f2a74b55bb98596405ab98775d5e4..ec2fe6d22620c770340f9df3ca4976dfd550d427 100644
--- a/base/files/file_path_watcher_win.cc
+++ b/base/files/file_path_watcher_win.cc
@@ -233,7 +233,6 @@ bool FilePathWatcherImpl::SetupWatchHandle(const FilePath& dir,
       error_code != ERROR_ACCESS_DENIED &&
       error_code != ERROR_SHARING_VIOLATION &&
       error_code != ERROR_DIRECTORY) {
-    using ::operator<<; // Pick the right operator<< below.
     DPLOG(ERROR) << "FindFirstChangeNotification failed for "
                  << dir.value();
     return false;