Unique_ptrify PPCallbacks ownership.

Unique_ptr creation stil needs to be moved earlier at some of the call sites.

llvm-svn: 217474
diff --git a/clang/unittests/Basic/SourceManagerTest.cpp b/clang/unittests/Basic/SourceManagerTest.cpp
index 8f066ba..1dda54d 100644
--- a/clang/unittests/Basic/SourceManagerTest.cpp
+++ b/clang/unittests/Basic/SourceManagerTest.cpp
@@ -303,7 +303,7 @@
   PP.Initialize(*Target);
 
   std::vector<MacroAction> Macros;
-  PP.addPPCallbacks(new MacroTracker(Macros));
+  PP.addPPCallbacks(llvm::make_unique<MacroTracker>(Macros));
 
   PP.EnterMainSourceFile();