Convert //base to use std::unique_ptr

base/files/important_file_writer.h

Index: base/files/important_file_writer.h
diff --git a/base/files/important_file_writer.h b/base/files/important_file_writer.h
index b28231efd24d8063b4ba23700ee48d07109f8197..71067fb09bdb23495e328ad78c68bf8437b98a9a 100644
--- a/base/files/important_file_writer.h
+++ b/base/files/important_file_writer.h
@@ -82,7 +82,7 @@ class BASE_EXPORT ImportantFileWriter : public NonThreadSafe {
 
   // Save |data| to target filename. Does not block. If there is a pending write
   // scheduled by ScheduleWrite(), it is cancelled.
-  void WriteNow(scoped_ptr<std::string> data);
+  void WriteNow(std::unique_ptr<std::string> data);
 
   // Schedule a save to target filename. Data will be serialized and saved
   // to disk after the commit interval. If another ScheduleWrite is issued