Replace NULL with nullptr or null in webrtc/base/.

BUG=webrtc:7147

Review-Url: https://codereview.webrtc.org/2718663005
Cr-Commit-Position: refs/heads/master@{#16878}
diff --git a/webrtc/base/virtualsocket_unittest.cc b/webrtc/base/virtualsocket_unittest.cc
index 4ee2c75..b884748 100644
--- a/webrtc/base/virtualsocket_unittest.cc
+++ b/webrtc/base/virtualsocket_unittest.cc
@@ -137,10 +137,10 @@
 
 class VirtualSocketServerTest : public testing::Test {
  public:
-  VirtualSocketServerTest() : ss_(new VirtualSocketServer(NULL)),
-                              kIPv4AnyAddress(IPAddress(INADDR_ANY), 0),
-                              kIPv6AnyAddress(IPAddress(in6addr_any), 0) {
-  }
+  VirtualSocketServerTest()
+      : ss_(new VirtualSocketServer(nullptr)),
+        kIPv4AnyAddress(IPAddress(INADDR_ANY), 0),
+        kIPv6AnyAddress(IPAddress(in6addr_any), 0) {}
 
   void CheckPortIncrementalization(const SocketAddress& post,
                                    const SocketAddress& pre) {
@@ -263,7 +263,7 @@
 
     // No pending server connections
     EXPECT_FALSE(sink.Check(server, testing::SSE_READ));
-    EXPECT_TRUE(NULL == server->Accept(&accept_addr));
+    EXPECT_TRUE(nullptr == server->Accept(&accept_addr));
     EXPECT_EQ(AF_UNSPEC, accept_addr.family());
 
     // Attempt connect to listening socket
@@ -287,7 +287,7 @@
     // Server has pending connection
     EXPECT_TRUE(sink.Check(server, testing::SSE_READ));
     Socket* accepted = server->Accept(&accept_addr);
-    EXPECT_TRUE(NULL != accepted);
+    EXPECT_TRUE(nullptr != accepted);
     EXPECT_NE(accept_addr, kEmptyAddr);
     EXPECT_EQ(accepted->GetRemoteAddress(), accept_addr);
 
@@ -330,7 +330,7 @@
 
     // No pending server connections
     EXPECT_FALSE(sink.Check(server, testing::SSE_READ));
-    EXPECT_TRUE(NULL == server->Accept(&accept_addr));
+    EXPECT_TRUE(nullptr == server->Accept(&accept_addr));
     EXPECT_EQ(accept_addr, nil_addr);
 
     // Connection failed
@@ -409,7 +409,7 @@
     // Server accepts connection
     EXPECT_TRUE(sink.Check(server.get(), testing::SSE_READ));
     std::unique_ptr<AsyncSocket> accepted(server->Accept(&accept_addr));
-    ASSERT_TRUE(NULL != accepted.get());
+    ASSERT_TRUE(nullptr != accepted.get());
     sink.Monitor(accepted.get());
 
     // Client closes before connection complets
@@ -686,7 +686,7 @@
   // incremental port behavior could ensure the 2 Binds result in different
   // address.
   void DelayTest(const SocketAddress& initial_addr) {
-    time_t seed = ::time(NULL);
+    time_t seed = ::time(nullptr);
     LOG(LS_VERBOSE) << "seed = " << seed;
     srand(static_cast<unsigned int>(seed));
 
@@ -766,7 +766,7 @@
       ss_->ProcessMessagesUntilIdle();
       EXPECT_TRUE(sink.Check(server, testing::SSE_READ));
       Socket* accepted = server->Accept(&accept_address);
-      EXPECT_TRUE(NULL != accepted);
+      EXPECT_TRUE(nullptr != accepted);
       EXPECT_NE(kEmptyAddr, accept_address);
       ss_->ProcessMessagesUntilIdle();
       EXPECT_TRUE(sink.Check(client, testing::SSE_OPEN));
@@ -777,7 +777,7 @@
       ss_->ProcessMessagesUntilIdle();
 
       EXPECT_FALSE(sink.Check(server, testing::SSE_READ));
-      EXPECT_TRUE(NULL == server->Accept(&accept_address));
+      EXPECT_TRUE(nullptr == server->Accept(&accept_address));
       EXPECT_EQ(accept_address, kEmptyAddr);
       EXPECT_EQ(client->GetState(), AsyncSocket::CS_CLOSED);
       EXPECT_FALSE(sink.Check(client, testing::SSE_OPEN));
@@ -818,9 +818,7 @@
   virtual void SetUp() {
     Thread::Current()->set_socketserver(ss_);
   }
-  virtual void TearDown() {
-    Thread::Current()->set_socketserver(NULL);
-  }
+  virtual void TearDown() { Thread::Current()->set_socketserver(nullptr); }
 
   VirtualSocketServer* ss_;
   const SocketAddress kIPv4AnyAddress;
@@ -1096,7 +1094,7 @@
             VirtualSocketServer::CreateDistribution(kTestMean[midx],
                                                     kStdDev,
                                                     kTestSamples[sidx]);
-        ASSERT_TRUE(NULL != f);
+        ASSERT_TRUE(nullptr != f);
         ASSERT_EQ(kTestSamples[sidx], f->size());
         double sum = 0;
         for (uint32_t i = 0; i < f->size(); ++i) {