Convert //sync from scoped_ptr to std::unique_ptr

sync/syncable/syncable_id.h

Index: sync/syncable/syncable_id.h
diff --git a/sync/syncable/syncable_id.h b/sync/syncable/syncable_id.h
index b2c0edfb890b4863c58a8c0a7ada9e4a77db0f5c..7dd09d8155175bb15164c0dffe7f45885467c9a8 100644
--- a/sync/syncable/syncable_id.h
+++ b/sync/syncable/syncable_id.h
@@ -7,11 +7,11 @@
 
 #include <iosfwd>
 #include <limits>
+#include <memory>
 #include <sstream>
 #include <string>
 
 #include "base/containers/hash_tables.h"
-#include "base/memory/scoped_ptr.h"
 #include "sync/base/sync_export.h"
 
 namespace base {
@@ -106,8 +106,8 @@ class SYNC_EXPORT Id {
   static Id GetRoot();
 
  private:
-  friend scoped_ptr<EntryKernel> UnpackEntry(sql::Statement* statement,
-                                             int* total_created_entries);
+  friend std::unique_ptr<EntryKernel> UnpackEntry(sql::Statement* statement,
+                                                  int* total_created_entries);
   friend void BindFields(const EntryKernel& entry,
                          sql::Statement* statement);
   SYNC_EXPORT friend std::ostream& operator<<(std::ostream& out, const Id& id);