update_engine: Replace scoped_ptr with std::unique_ptr.

BUG=None
TEST=`FEATURES=test emerge-$BOARD update_engine`
TEST=`USE='clang asan' FEATURES=test emerge-$BOARD update_engine`

Change-Id: I55a2f7f53675faaac20ba25f72ed52cf938d7744
Reviewed-on: https://chromium-review.googlesource.com/224189
Tested-by: Ben Chan <benchan@chromium.org>
Reviewed-by: Alex Deymo <deymo@chromium.org>
Commit-Queue: Ben Chan <benchan@chromium.org>
diff --git a/utils.h b/utils.h
index 5cd6595..647f52c 100644
--- a/utils.h
+++ b/utils.h
@@ -10,6 +10,7 @@
 
 #include <algorithm>
 #include <map>
+#include <memory>
 #include <set>
 #include <string>
 #include <vector>
@@ -580,7 +581,7 @@
 };
 
 // A base::FreeDeleter that frees memory using g_free(). Useful when
-// integrating with GLib since it can be used with scoped_ptr to
+// integrating with GLib since it can be used with std::unique_ptr to
 // automatically free memory when going out of scope.
 struct GLibFreeDeleter : public base::FreeDeleter {
   inline void operator()(void *ptr) const {
@@ -589,7 +590,7 @@
 };
 
 // A base::FreeDeleter that frees memory using g_strfreev(). Useful
-// when integrating with GLib since it can be used with scoped_ptr to
+// when integrating with GLib since it can be used with std::unique_ptr to
 // automatically free memory when going out of scope.
 struct GLibStrvFreeDeleter : public base::FreeDeleter {
   inline void operator()(void *ptr) const {