Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -2618,7 +2618,6 @@
 }
 
 static void ParsePreprocessorArgs(PreprocessorOptions &Opts, ArgList &Args,
-                                  FileManager &FileMgr,
                                   DiagnosticsEngine &Diags,
                                   frontend::ActionKind Action) {
   using namespace options;
@@ -2840,12 +2839,7 @@
       !LangOpts.Sanitize.has(SanitizerKind::Address) &&
       !LangOpts.Sanitize.has(SanitizerKind::Memory);
 
-  // FIXME: ParsePreprocessorArgs uses the FileManager to read the contents of
-  // PCH file and find the original header name. Remove the need to do that in
-  // ParsePreprocessorArgs and remove the FileManager
-  // parameters from the function and the "FileManager.h" #include.
-  FileManager FileMgr(Res.getFileSystemOpts());
-  ParsePreprocessorArgs(Res.getPreprocessorOpts(), Args, FileMgr, Diags,
+  ParsePreprocessorArgs(Res.getPreprocessorOpts(), Args, Diags,
                         Res.getFrontendOpts().ProgramAction);
   ParsePreprocessorOutputArgs(Res.getPreprocessorOutputOpts(), Args,
                               Res.getFrontendOpts().ProgramAction);