Replace NULL with nullptr.

extensions/browser/api/cast_channel/cast_framer.h

Index: extensions/browser/api/cast_channel/cast_framer.h
diff --git a/extensions/browser/api/cast_channel/cast_framer.h b/extensions/browser/api/cast_channel/cast_framer.h
index 4bfe0023d41324fe8e66cbd117d848ac5c840ff3..3d899146947dd7db92b2f3812ef8e4d454ec5392 100644
--- a/extensions/browser/api/cast_channel/cast_framer.h
+++ b/extensions/browser/api/cast_channel/cast_framer.h
@@ -5,6 +5,8 @@
 #ifndef EXTENSIONS_BROWSER_API_CAST_CHANNEL_CAST_FRAMER_H_
 #define EXTENSIONS_BROWSER_API_CAST_CHANNEL_CAST_FRAMER_H_
 
+#include <string>
+
 #include "base/basictypes.h"
 #include "extensions/common/api/cast_channel.h"
 #include "net/base/io_buffer.h"
@@ -42,7 +44,7 @@ class MessageFramer {
   // |error| The result of the ingest operation. Set to CHANNEL_ERROR_NONE
   //         if no error occurred.
   // Returns A pointer to a parsed CastMessage if a message was received
-  //         in its entirety, NULL otherwise.
+  //         in its entirety, nullptr otherwise.
   scoped_ptr<CastMessage> Ingest(size_t num_bytes,
                                  size_t* message_length,
                                  ChannelError* error);