Misc cleanup in net/spdy/core.

net/spdy/core/spdy_pinnable_buffer_piece.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/spdy/core/spdy_pinnable_buffer_piece.h"
 
 #include <new>
 
 namespace net {
 
 SpdyPinnableBufferPiece::SpdyPinnableBufferPiece()
-    : buffer_(0), length_(0) {}
+    : buffer_(nullptr), length_(0) {}
 
 SpdyPinnableBufferPiece::~SpdyPinnableBufferPiece() {}
 
 void SpdyPinnableBufferPiece::Pin() {
-  if (!storage_ && buffer_ != NULL && length_ != 0) {
+  if (!storage_ && buffer_ != nullptr && length_ != 0) {
     storage_.reset(new char[length_]);
     std::copy(buffer_, buffer_ + length_, storage_.get());
     buffer_ = storage_.get();
   }
 }
 
 void SpdyPinnableBufferPiece::Swap(SpdyPinnableBufferPiece* other) {
   size_t length = length_;
   length_ = other->length_;
   other->length_ = length;
 
   const char* buffer = buffer_;
   buffer_ = other->buffer_;
   other->buffer_ = buffer;
 
   storage_.swap(other->storage_);
 }
 
 }  // namespace net