QUIC - (no behavior change) s/NULL/nullptr/g in .../quic/...

net/quic/quic_data_writer.cc

Index: net/quic/quic_data_writer.cc
diff --git a/net/quic/quic_data_writer.cc b/net/quic/quic_data_writer.cc
index 70b0fdaed31f8e5abf7d2250a4418052e3fea390..11b6b55042bc06a1fc5c850de3d1a5011a51dcd7 100644
--- a/net/quic/quic_data_writer.cc
+++ b/net/quic/quic_data_writer.cc
@@ -28,7 +28,7 @@ QuicDataWriter::~QuicDataWriter() {
 
 char* QuicDataWriter::take() {
   char* rv = buffer_;
-  buffer_ = NULL;
+  buffer_ = nullptr;
   capacity_ = 0;
   length_ = 0;
   return rv;
@@ -119,11 +119,11 @@ bool QuicDataWriter::WriteIOVector(const IOVector& data) {
 
 char* QuicDataWriter::BeginWrite(size_t length) {
   if (length_ > capacity_) {
-    return NULL;
+    return nullptr;
   }
 
   if (capacity_ - length_ < length) {
-    return NULL;
+    return nullptr;
   }
 
 #ifdef ARCH_CPU_64_BITS