[QUIC] Remove using from headers and make git cl lint happy.

Using directives:
* Remove using std::string, std::list, and base::StringPiece directives from
  header files.
* Add namespace qualifiers to string, list, and StringPiece  in .cc files
  (or add using directives where it makes sense).
* Move using directives consistently after #includes and before namespace.

git cl lint:
* #include std headers that are used.
* Fix #include orders.
* Remove two unnecessary semicolons and add one space.
* Add explicit qualifier to a constructor with one argument.
* Remove explicit qualifier from a constructor with zero arguments.
* Add argument name to one method declaration.
* Use static_cast<> instead of C-style cast.
* Fix one header guard closing #endif comment.

This CL lands server change 118254530 by bnc.

Review URL: https://codereview.chromium.org/1839523002

Cr-Commit-Position: refs/heads/master@{#384899}
diff --git a/net/quic/p2p/quic_p2p_session.cc b/net/quic/p2p/quic_p2p_session.cc
index 0be062b..7b411e02 100644
--- a/net/quic/p2p/quic_p2p_session.cc
+++ b/net/quic/p2p/quic_p2p_session.cc
@@ -69,7 +69,7 @@
 }
 
 void QuicP2PSession::OnConnectionClosed(QuicErrorCode error,
-                                        const string& error_details,
+                                        const std::string& error_details,
                                         ConnectionCloseSource source) {
   QuicSession::OnConnectionClosed(error, error_details, source);