Convert //extensions/browser/api from scoped_ptr to std::unique_ptr

extensions/browser/api/serial/serial_connection.h

Index: extensions/browser/api/serial/serial_connection.h
diff --git a/extensions/browser/api/serial/serial_connection.h b/extensions/browser/api/serial/serial_connection.h
index 428e2d66ea4dc844a06672f1ff166d6acf5e172b..d9ab5d797564cc8857e127d82f373e0a13a19d82 100644
--- a/extensions/browser/api/serial/serial_connection.h
+++ b/extensions/browser/api/serial/serial_connection.h
@@ -187,11 +187,11 @@ class SerialConnection : public ApiResource,
 
   // Closure which will trigger a receive timeout unless cancelled. Reset on
   // initialization and after every successful Receive().
-  scoped_ptr<TimeoutTask> receive_timeout_task_;
+  std::unique_ptr<TimeoutTask> receive_timeout_task_;
 
   // Write timeout closure. Reset on initialization and after every successful
   // Send().
-  scoped_ptr<TimeoutTask> send_timeout_task_;
+  std::unique_ptr<TimeoutTask> send_timeout_task_;
 
   scoped_refptr<net::IOBuffer> receive_buffer_;