Update scoped_ptr references to be unique_ptr in src/base comments.

base/debug/leak_tracker_unittest.cc

Index: base/debug/leak_tracker_unittest.cc
diff --git a/base/debug/leak_tracker_unittest.cc b/base/debug/leak_tracker_unittest.cc
index 8b4c5681e0dc24c01d221324cfa1e1a5a6d8da51..b9ecdcf3c9745a9192acdc5a3276f22f4513da43 100644
--- a/base/debug/leak_tracker_unittest.cc
+++ b/base/debug/leak_tracker_unittest.cc
@@ -30,7 +30,7 @@ TEST(LeakTrackerTest, NotEnabled) {
   EXPECT_EQ(-1, LeakTracker<ClassA>::NumLiveInstances());
   EXPECT_EQ(-1, LeakTracker<ClassB>::NumLiveInstances());
 
-  // Use scoped_ptr so compiler doesn't complain about unused variables.
+  // Use unique_ptr so compiler doesn't complain about unused variables.
   std::unique_ptr<ClassA> a1(new ClassA);
   std::unique_ptr<ClassB> b1(new ClassB);
   std::unique_ptr<ClassB> b2(new ClassB);