Replace NULL with nullptr in all C++ files.

webrtc/modules/video_coding/encoded_frame.cc

Index: webrtc/modules/video_coding/encoded_frame.cc
diff --git a/webrtc/modules/video_coding/encoded_frame.cc b/webrtc/modules/video_coding/encoded_frame.cc
index fb12c5bc68da0083605600aaf06f028255788e37..39de2e11279dd5d61340f7c41eba2069cde02592 100644
--- a/webrtc/modules/video_coding/encoded_frame.cc
+++ b/webrtc/modules/video_coding/encoded_frame.cc
@@ -33,10 +33,10 @@ VCMEncodedFrame::VCMEncodedFrame(const webrtc::EncodedImage& rhs)
       _codec(kVideoCodecUnknown),
       _rotation_set(false) {
   _codecSpecificInfo.codecType = kVideoCodecUnknown;
-  _buffer = NULL;
+  _buffer = nullptr;
   _size = 0;
   _length = 0;
-  if (rhs._buffer != NULL) {
+  if (rhs._buffer != nullptr) {
     VerifyAndAllocate(rhs._length +
                       EncodedImage::GetBufferPaddingBytes(_codec));
     memcpy(_buffer, rhs._buffer, rhs._length);
@@ -51,10 +51,10 @@ VCMEncodedFrame::VCMEncodedFrame(const VCMEncodedFrame& rhs)
       _codecSpecificInfo(rhs._codecSpecificInfo),
       _codec(rhs._codec),
       _rotation_set(rhs._rotation_set) {
-  _buffer = NULL;
+  _buffer = nullptr;
   _size = 0;
   _length = 0;
-  if (rhs._buffer != NULL) {
+  if (rhs._buffer != nullptr) {
     VerifyAndAllocate(rhs._length +
                       EncodedImage::GetBufferPaddingBytes(_codec));
     memcpy(_buffer, rhs._buffer, rhs._length);
@@ -68,9 +68,9 @@ VCMEncodedFrame::~VCMEncodedFrame() {
 
 void VCMEncodedFrame::Free() {
   Reset();
-  if (_buffer != NULL) {
+  if (_buffer != nullptr) {
     delete[] _buffer;
-    _buffer = NULL;
+    _buffer = nullptr;
   }
 }