Replace NULL with nullptr in all C++ files.

webrtc/pc/peerconnectionendtoend_unittest.cc

Index: webrtc/pc/peerconnectionendtoend_unittest.cc
diff --git a/webrtc/pc/peerconnectionendtoend_unittest.cc b/webrtc/pc/peerconnectionendtoend_unittest.cc
index df41dac2a8c0fedbd31c010c01a6c79e8aa45682..d42f963a8547fa91a997b80129328db5008703e5 100644
--- a/webrtc/pc/peerconnectionendtoend_unittest.cc
+++ b/webrtc/pc/peerconnectionendtoend_unittest.cc
@@ -59,9 +59,7 @@ class PeerConnectionEndToEndTest
 #endif
   }
 
-  void CreatePcs() {
-    CreatePcs(NULL);
-  }
+  void CreatePcs() { CreatePcs(nullptr); }
 
   void CreatePcs(const MediaConstraintsInterface* pc_constraints) {
     EXPECT_TRUE(caller_->CreatePc(pc_constraints, config_));
@@ -88,9 +86,7 @@ class PeerConnectionEndToEndTest
                                 video, video_constraints);
   }
 
-  void Negotiate() {
-    caller_->CreateOffer(NULL);
-  }
+  void Negotiate() { caller_->CreateOffer(nullptr); }
 
   void WaitForCallEstablished() {
     caller_->WaitForCallEstablished();