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/multi_range_http_fetcher.h b/multi_range_http_fetcher.h
index 5b167b2..ae25f45 100644
--- a/multi_range_http_fetcher.h
+++ b/multi_range_http_fetcher.h
@@ -6,12 +6,11 @@
 #define UPDATE_ENGINE_MULTI_RANGE_HTTP_FETCHER_H_
 
 #include <deque>
+#include <memory>
 #include <string>
 #include <utility>
 #include <vector>
 
-#include <base/memory/scoped_ptr.h>
-
 #include "update_engine/http_fetcher.h"
 
 // This class is a simple wrapper around an HttpFetcher. The client
@@ -139,7 +138,7 @@
 
   void Reset();
 
-  scoped_ptr<HttpFetcher> base_fetcher_;
+  std::unique_ptr<HttpFetcher> base_fetcher_;
 
   // If true, do not send any more data or TransferComplete to the delegate.
   bool base_fetcher_active_;