[C++11] Add 'override' keyword to virtual methods that override their base class.

llvm-svn: 203758
diff --git a/clang/lib/Frontend/HeaderIncludeGen.cpp b/clang/lib/Frontend/HeaderIncludeGen.cpp
index 00ff637..6d2e378 100644
--- a/clang/lib/Frontend/HeaderIncludeGen.cpp
+++ b/clang/lib/Frontend/HeaderIncludeGen.cpp
@@ -40,9 +40,9 @@
       delete OutputFile;
   }
 
-  virtual void FileChanged(SourceLocation Loc, FileChangeReason Reason,
-                           SrcMgr::CharacteristicKind FileType,
-                           FileID PrevFID);
+  void FileChanged(SourceLocation Loc, FileChangeReason Reason,
+                   SrcMgr::CharacteristicKind FileType,
+                   FileID PrevFID) override;
 };
 }