Replace NULL with nullptr in all C++ files.

webrtc/pc/mediastream_unittest.cc

Index: webrtc/pc/mediastream_unittest.cc
diff --git a/webrtc/pc/mediastream_unittest.cc b/webrtc/pc/mediastream_unittest.cc
index e2e3985507cd31b693d95b7b7b3040715a46323d..a4af597f9bd053389466091b41818e2297adedfc 100644
--- a/webrtc/pc/mediastream_unittest.cc
+++ b/webrtc/pc/mediastream_unittest.cc
@@ -54,16 +54,16 @@ class MediaStreamTest: public testing::Test {
  protected:
   virtual void SetUp() {
     stream_ = MediaStream::Create(kStreamLabel1);
-    ASSERT_TRUE(stream_.get() != NULL);
+    ASSERT_TRUE(stream_.get() != nullptr);
 
     video_track_ =
         VideoTrack::Create(kVideoTrackId, FakeVideoTrackSource::Create());
-    ASSERT_TRUE(video_track_.get() != NULL);
+    ASSERT_TRUE(video_track_.get() != nullptr);
     EXPECT_EQ(MediaStreamTrackInterface::kLive, video_track_->state());
 
-    audio_track_ = AudioTrack::Create(kAudioTrackId, NULL);
+    audio_track_ = AudioTrack::Create(kAudioTrackId, nullptr);
 
-    ASSERT_TRUE(audio_track_.get() != NULL);
+    ASSERT_TRUE(audio_track_.get() != nullptr);
     EXPECT_EQ(MediaStreamTrackInterface::kLive, audio_track_->state());
 
     EXPECT_TRUE(stream_->AddTrack(video_track_));
@@ -135,8 +135,10 @@ TEST_F(MediaStreamTest, RemoveTrack) {
   EXPECT_EQ(0u, stream_->GetVideoTracks().size());
   EXPECT_EQ(0u, stream_->GetVideoTracks().size());
 
-  EXPECT_FALSE(stream_->RemoveTrack(static_cast<AudioTrackInterface*>(NULL)));
-  EXPECT_FALSE(stream_->RemoveTrack(static_cast<VideoTrackInterface*>(NULL)));
+  EXPECT_FALSE(
+      stream_->RemoveTrack(static_cast<AudioTrackInterface*>(nullptr)));
+  EXPECT_FALSE(
+      stream_->RemoveTrack(static_cast<VideoTrackInterface*>(nullptr)));
 }
 
 TEST_F(MediaStreamTest, ChangeVideoTrack) {