Index: include/clang/Lex/PPCallbacks.h
===================================================================
--- include/clang/Lex/PPCallbacks.h
+++ include/clang/Lex/PPCallbacks.h
@@ -54,11 +54,12 @@
   /// \brief Callback invoked whenever a source file is skipped as the result
   /// of header guard optimization.
   ///
-  /// \param ParentFile The file that \#included the skipped file.
+  /// \param SkippedFile The file that is skipped instead of entering \#include
   ///
-  /// \param FilenameTok The token in ParentFile that indicates the
-  /// skipped file.
-  virtual void FileSkipped(const FileEntry &ParentFile,
+  /// \param FilenameTok The file name token in \#include "FileName" directive
+  /// or macro expanded file name token from \#include MACRO(PARAMS) directive.
+  /// Note that FilenameTok contains corresponding quotes/angles symbols.
+  virtual void FileSkipped(const FileEntry &SkippedFile,
                            const Token &FilenameTok,
                            SrcMgr::CharacteristicKind FileType) {
   }
@@ -336,11 +337,11 @@
     Second->FileChanged(Loc, Reason, FileType, PrevFID);
   }
 
-  void FileSkipped(const FileEntry &ParentFile,
+  void FileSkipped(const FileEntry &SkippedFile,
                    const Token &FilenameTok,
                    SrcMgr::CharacteristicKind FileType) override {
-    First->FileSkipped(ParentFile, FilenameTok, FileType);
-    Second->FileSkipped(ParentFile, FilenameTok, FileType);
+    First->FileSkipped(SkippedFile, FilenameTok, FileType);
+    Second->FileSkipped(SkippedFile, FilenameTok, FileType);
   }
 
   bool FileNotFound(StringRef FileName,
Index: lib/Frontend/Rewrite/InclusionRewriter.cpp
===================================================================
--- lib/Frontend/Rewrite/InclusionRewriter.cpp
+++ lib/Frontend/Rewrite/InclusionRewriter.cpp
@@ -61,7 +61,7 @@
   void FileChanged(SourceLocation Loc, FileChangeReason Reason,
                    SrcMgr::CharacteristicKind FileType,
                    FileID PrevFID) override;
-  void FileSkipped(const FileEntry &ParentFile, const Token &FilenameTok,
+  void FileSkipped(const FileEntry &SkippedFile, const Token &FilenameTok,
                    SrcMgr::CharacteristicKind FileType) override;
   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
                           StringRef FileName, bool IsAngled,
@@ -153,7 +153,7 @@
 
 /// Called whenever an inclusion is skipped due to canonical header protection
 /// macros.
-void InclusionRewriter::FileSkipped(const FileEntry &/*ParentFile*/,
+void InclusionRewriter::FileSkipped(const FileEntry &/*SkippedFile*/,
                                     const Token &/*FilenameTok*/,
                                     SrcMgr::CharacteristicKind /*FileType*/) {
   assert(LastInsertedFileChange != FileChanges.end() && "A file, that wasn't "