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/evaluation_context_unittest.cc b/update_manager/evaluation_context_unittest.cc
index e59b160..014d10c 100644
--- a/update_manager/evaluation_context_unittest.cc
+++ b/update_manager/evaluation_context_unittest.cc
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <memory>
 #include <string>
 
 #include <base/bind.h>
@@ -23,6 +24,7 @@
 using chromeos_update_engine::RunGMainLoopMaxIterations;
 using chromeos_update_engine::RunGMainLoopUntil;
 using std::string;
+using std::unique_ptr;
 using testing::Return;
 using testing::StrictMock;
 using testing::_;
@@ -75,7 +77,7 @@
     fake_clock_.SetWallclockTime(Time::FromTimeT(1141262625));
     eval_ctx_ = new EvaluationContext(
         &fake_clock_, default_timeout_, default_timeout_,
-        scoped_ptr<base::Callback<void(EvaluationContext*)>>(nullptr));
+        unique_ptr<base::Callback<void(EvaluationContext*)>>(nullptr));
   }
 
   virtual void TearDown() {