Replace scoped_ptr with unique_ptr in webrtc/p2p/

But keep #including scoped_ptr.h in .h files, so as not to break
WebRTC users who expect those .h files to give them rtc::scoped_ptr.

BUG=webrtc:5520

Review URL: https://codereview.webrtc.org/1923163003

Cr-Commit-Position: refs/heads/master@{#12532}
diff --git a/webrtc/p2p/client/portallocator_unittest.cc b/webrtc/p2p/client/portallocator_unittest.cc
index a76900a..2181903 100644
--- a/webrtc/p2p/client/portallocator_unittest.cc
+++ b/webrtc/p2p/client/portallocator_unittest.cc
@@ -8,6 +8,8 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+#include <memory>
+
 #include "webrtc/p2p/base/basicpacketsocketfactory.h"
 #include "webrtc/p2p/base/p2pconstants.h"
 #include "webrtc/p2p/base/p2ptransportchannel.h"
@@ -370,19 +372,19 @@
     allocator().set_step_delay(cricket::kMinimumStepDelay);
   }
 
-  rtc::scoped_ptr<rtc::PhysicalSocketServer> pss_;
-  rtc::scoped_ptr<rtc::VirtualSocketServer> vss_;
-  rtc::scoped_ptr<rtc::FirewallSocketServer> fss_;
+  std::unique_ptr<rtc::PhysicalSocketServer> pss_;
+  std::unique_ptr<rtc::VirtualSocketServer> vss_;
+  std::unique_ptr<rtc::FirewallSocketServer> fss_;
   rtc::SocketServerScope ss_scope_;
-  rtc::scoped_ptr<rtc::NATServer> nat_server_;
+  std::unique_ptr<rtc::NATServer> nat_server_;
   rtc::NATSocketFactory nat_factory_;
-  rtc::scoped_ptr<rtc::BasicPacketSocketFactory> nat_socket_factory_;
-  rtc::scoped_ptr<cricket::TestStunServer> stun_server_;
+  std::unique_ptr<rtc::BasicPacketSocketFactory> nat_socket_factory_;
+  std::unique_ptr<cricket::TestStunServer> stun_server_;
   cricket::TestRelayServer relay_server_;
   cricket::TestTurnServer turn_server_;
   rtc::FakeNetworkManager network_manager_;
-  rtc::scoped_ptr<cricket::BasicPortAllocator> allocator_;
-  rtc::scoped_ptr<cricket::PortAllocatorSession> session_;
+  std::unique_ptr<cricket::BasicPortAllocator> allocator_;
+  std::unique_ptr<cricket::PortAllocatorSession> session_;
   std::vector<cricket::PortInterface*> ports_;
   std::vector<cricket::Candidate> candidates_;
   bool candidate_allocation_done_;