Replace NULL with nullptr in all C++ files.

webrtc/pc/srtpfilter_unittest.cc

 /*
  *  Copyright 2004 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 560 matching lines @@
 }
 
 #if defined(ENABLE_EXTERNAL_AUTH)
 TEST_F(SrtpFilterTest, TestGetSendAuthParams) {
   EXPECT_TRUE(f1_.SetRtpParams(rtc::SRTP_AES128_CM_SHA1_32, kTestKey1,
                                kTestKeyLen, rtc::SRTP_AES128_CM_SHA1_32,
                                kTestKey2, kTestKeyLen));
   EXPECT_TRUE(f1_.SetRtcpParams(rtc::SRTP_AES128_CM_SHA1_32, kTestKey1,
                                 kTestKeyLen, rtc::SRTP_AES128_CM_SHA1_32,
                                 kTestKey2, kTestKeyLen));
-  uint8_t* auth_key = NULL;
+  uint8_t* auth_key = nullptr;
   int auth_key_len = 0, auth_tag_len = 0;
   EXPECT_TRUE(f1_.GetRtpAuthParams(&auth_key, &auth_key_len, &auth_tag_len));
-  EXPECT_TRUE(auth_key != NULL);
+  EXPECT_TRUE(auth_key != nullptr);
   EXPECT_EQ(20, auth_key_len);
   EXPECT_EQ(4, auth_tag_len);
 }
 #endif
 
 class SrtpSessionTest : public testing::Test {
  protected:
   virtual void SetUp() {
     rtp_len_ = sizeof(kPcmuFrame);
     rtcp_len_ = sizeof(kRtcpReport);
@@ skipping 337 matching lines @@
   srtp_stat_.AddUnprotectRtcpResult(srtp_err_status_fail);
   EXPECT_EQ(-1, mode_);
   EXPECT_EQ(cricket::SrtpFilter::ERROR_NONE, error_);
   // Now the error will be triggered again.
   Reset();
   rtc::Thread::Current()->SleepMs(210);
   srtp_stat_.AddUnprotectRtcpResult(srtp_err_status_fail);
   EXPECT_EQ(cricket::SrtpFilter::UNPROTECT, mode_);
   EXPECT_EQ(cricket::SrtpFilter::ERROR_FAIL, error_);
 }