Replace OwningPtr with std::unique_ptr.

This compiles cleanly with lldb/lld/clang-tools-extra/llvm.

llvm-svn: 203279
diff --git a/clang/unittests/ASTMatchers/Dynamic/RegistryTest.cpp b/clang/unittests/ASTMatchers/Dynamic/RegistryTest.cpp
index 8426649..1d81f2f 100644
--- a/clang/unittests/ASTMatchers/Dynamic/RegistryTest.cpp
+++ b/clang/unittests/ASTMatchers/Dynamic/RegistryTest.cpp
@@ -370,7 +370,7 @@
 
 TEST_F(RegistryTest, Errors) {
   // Incorrect argument count.
-  OwningPtr<Diagnostics> Error(new Diagnostics());
+  std::unique_ptr<Diagnostics> Error(new Diagnostics());
   EXPECT_TRUE(constructMatcher("hasInitializer", Error.get()).isNull());
   EXPECT_EQ("Incorrect argument count. (Expected = 1) != (Actual = 0)",
             Error->toString());