Remove various 'using std::' statements from QUIC code and use

net/quic/core/frames/quic_path_close_frame.cc

Index: net/quic/core/frames/quic_path_close_frame.cc
diff --git a/net/quic/core/frames/quic_path_close_frame.cc b/net/quic/core/frames/quic_path_close_frame.cc
index 6e4fbed24bf4ffb8f367cb2257e845db33d24297..f2b751aca025e8297ad62a3c3439aab33f9922d0 100644
--- a/net/quic/core/frames/quic_path_close_frame.cc
+++ b/net/quic/core/frames/quic_path_close_frame.cc
@@ -4,13 +4,12 @@
 
 #include "net/quic/core/frames/quic_path_close_frame.h"
 
-using std::ostream;
-
 namespace net {
 
 QuicPathCloseFrame::QuicPathCloseFrame(QuicPathId path_id) : path_id(path_id) {}
 
-ostream& operator<<(ostream& os, const QuicPathCloseFrame& path_close_frame) {
+std::ostream& operator<<(std::ostream& os,
+                         const QuicPathCloseFrame& path_close_frame) {
   os << "{ path_id: " << static_cast<int>(path_close_frame.path_id) << " }\n";
   return os;
 }