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/update_manager/update_manager_unittest.cc b/update_manager/update_manager_unittest.cc
index 9e21716..b263fc8 100644
--- a/update_manager/update_manager_unittest.cc
+++ b/update_manager/update_manager_unittest.cc
@@ -5,13 +5,13 @@
 #include <unistd.h>
 
 #include <algorithm>
+#include <memory>
 #include <string>
 #include <tuple>
 #include <utility>
 #include <vector>
 
 #include <base/bind.h>
-#include <base/memory/scoped_ptr.h>
 #include <base/time/time.h>
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
@@ -33,6 +33,7 @@
 using std::pair;
 using std::string;
 using std::tuple;
+using std::unique_ptr;
 using std::vector;
 using testing::Return;
 using testing::StrictMock;
@@ -68,7 +69,7 @@
 
   FakeState* fake_state_;  // Owned by the umut_.
   FakeClock fake_clock_;
-  scoped_ptr<UpdateManager> umut_;
+  unique_ptr<UpdateManager> umut_;
 };
 
 // The FailingPolicy implements a single method and make it always fail. This