Mojo: NULL -> nullptr in mojo/system and mojo/embedder.

mojo/system/dispatcher.h

 // Copyright 2013 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.
 
 #ifndef MOJO_SYSTEM_DISPATCHER_H_
 #define MOJO_SYSTEM_DISPATCHER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 354 matching lines @@
 };
 
 // Wrapper around a |Dispatcher| pointer, while it's being processed to be
 // passed in a message pipe. See the comment about
 // |Dispatcher::HandleTableAccess| for more details.
 //
 // Note: This class is deliberately "thin" -- no more expensive than a
 // |Dispatcher*|.
 class MOJO_SYSTEM_IMPL_EXPORT DispatcherTransport {
  public:
-  DispatcherTransport() : dispatcher_(NULL) {}
+  DispatcherTransport() : dispatcher_(nullptr) {}
 
   void End();
 
   Dispatcher::Type GetType() const { return dispatcher_->GetType(); }
   bool IsBusy() const { return dispatcher_->IsBusyNoLock(); }
   void Close() { dispatcher_->CloseNoLock(); }
   scoped_refptr<Dispatcher> CreateEquivalentDispatcherAndClose() {
     return dispatcher_->CreateEquivalentDispatcherAndCloseNoLock();
   }
 
@@ skipping 10 matching lines @@
 
   Dispatcher* dispatcher_;
 
   // Copy and assign allowed.
 };
 
 }  // namespace system
 }  // namespace mojo
 
 #endif  // MOJO_SYSTEM_DISPATCHER_H_