diff --git a/clang/include/clang/Frontend/ChainedIncludesSource.h b/clang/include/clang/Frontend/ChainedIncludesSource.h
deleted file mode 100644
index 676e749fb153..000000000000
--- a/clang/include/clang/Frontend/ChainedIncludesSource.h
+++ /dev/null
@@ -1,75 +0,0 @@
-//===- ChainedIncludesSource.h - Chained PCHs in Memory ---------*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-//  This file defines the ChainedIncludesSource class, which converts headers
-//  to chained PCHs in memory, mainly used for testing.
-//
-//===----------------------------------------------------------------------===//
-#ifndef LLVM_CLANG_SERIALIZATION_CHAINEDINCLUDESSOURCE_H
-#define LLVM_CLANG_SERIALIZATION_CHAINEDINCLUDESSOURCE_H
-
-#include "clang/Sema/ExternalSemaSource.h"
-#include <vector>
-
-namespace clang {
-  class CompilerInstance;
-
-class ChainedIncludesSource : public ExternalSemaSource {
-public:
-  virtual ~ChainedIncludesSource();
-
-  static IntrusiveRefCntPtr<ChainedIncludesSource> create(CompilerInstance &CI);
-
-  ExternalSemaSource &getFinalReader() const { return *FinalReader; }
-
-private:
-  std::vector<CompilerInstance *> CIs;
-  IntrusiveRefCntPtr<ExternalSemaSource> FinalReader;
-
-  
-protected:
-
-//===----------------------------------------------------------------------===//
-// ExternalASTSource interface.
-//===----------------------------------------------------------------------===//
-
-  Decl *GetExternalDecl(uint32_t ID) override;
-  Selector GetExternalSelector(uint32_t ID) override;
-  uint32_t GetNumExternalSelectors() override;
-  Stmt *GetExternalDeclStmt(uint64_t Offset) override;
-  CXXBaseSpecifier *GetExternalCXXBaseSpecifiers(uint64_t Offset) override;
-  bool FindExternalVisibleDeclsByName(const DeclContext *DC,
-                                      DeclarationName Name) override;
-  ExternalLoadResult FindExternalLexicalDecls(const DeclContext *DC,
-                                bool (*isKindWeWant)(Decl::Kind),
-                                SmallVectorImpl<Decl*> &Result) override;
-  void CompleteType(TagDecl *Tag) override;
-  void CompleteType(ObjCInterfaceDecl *Class) override;
-  void StartedDeserializing() override;
-  void FinishedDeserializing() override;
-  void StartTranslationUnit(ASTConsumer *Consumer) override;
-  void PrintStats() override;
-
-  /// Return the amount of memory used by memory buffers, breaking down
-  /// by heap-backed versus mmap'ed memory.
-  void getMemoryBufferSizes(MemoryBufferSizes &sizes) const override;
-
-//===----------------------------------------------------------------------===//
-// ExternalSemaSource interface.
-//===----------------------------------------------------------------------===//
-
-  void InitializeSema(Sema &S) override;
-  void ForgetSema() override;
-  void ReadMethodPool(Selector Sel) override;
-  bool LookupUnqualified(LookupResult &R, Scope *S) override;
-};
-
-}
-
-#endif
diff --git a/clang/include/clang/Frontend/Utils.h b/clang/include/clang/Frontend/Utils.h
index eb417320b905..4c0a7b7a9c66 100644
--- a/clang/include/clang/Frontend/Utils.h
+++ b/clang/include/clang/Frontend/Utils.h
@@ -39,6 +39,7 @@ class Decl;
 class DependencyOutputOptions;
 class DiagnosticsEngine;
 class DiagnosticOptions;
+class ExternalSemaSource;
 class FileManager;
 class HeaderSearch;
 class HeaderSearchOptions;
@@ -162,6 +163,12 @@ void AttachHeaderIncludeGen(Preprocessor &PP, bool ShowAllHeaders = false,
 /// a seekable stream.
 void CacheTokens(Preprocessor &PP, llvm::raw_fd_ostream* OS);
 
+/// The ChainedIncludesSource class converts headers to chained PCHs in
+/// memory, mainly for testing.
+IntrusiveRefCntPtr<ExternalSemaSource>
+createChainedIncludesSource(CompilerInstance &CI,
+                            IntrusiveRefCntPtr<ExternalSemaSource> &Reader);
+
 /// createInvocationFromCommandLine - Construct a compiler invocation object for
 /// a command line argument vector.
 ///
diff --git a/clang/lib/Frontend/ChainedIncludesSource.cpp b/clang/lib/Frontend/ChainedIncludesSource.cpp
index 387f67118e95..e6e73ac963fb 100644
--- a/clang/lib/Frontend/ChainedIncludesSource.cpp
+++ b/clang/lib/Frontend/ChainedIncludesSource.cpp
@@ -12,7 +12,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang/Frontend/ChainedIncludesSource.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Frontend/ASTUnit.h"
 #include "clang/Frontend/CompilerInstance.h"
@@ -25,6 +24,54 @@
 
 using namespace clang;
 
+namespace {
+class ChainedIncludesSource : public ExternalSemaSource {
+public:
+  virtual ~ChainedIncludesSource();
+
+  ExternalSemaSource &getFinalReader() const { return *FinalReader; }
+
+  std::vector<CompilerInstance *> CIs;
+  IntrusiveRefCntPtr<ExternalSemaSource> FinalReader;
+
+protected:
+  //===----------------------------------------------------------------------===//
+  // ExternalASTSource interface.
+  //===----------------------------------------------------------------------===//
+
+  Decl *GetExternalDecl(uint32_t ID) override;
+  Selector GetExternalSelector(uint32_t ID) override;
+  uint32_t GetNumExternalSelectors() override;
+  Stmt *GetExternalDeclStmt(uint64_t Offset) override;
+  CXXBaseSpecifier *GetExternalCXXBaseSpecifiers(uint64_t Offset) override;
+  bool FindExternalVisibleDeclsByName(const DeclContext *DC,
+                                      DeclarationName Name) override;
+  ExternalLoadResult
+  FindExternalLexicalDecls(const DeclContext *DC,
+                           bool (*isKindWeWant)(Decl::Kind),
+                           SmallVectorImpl<Decl *> &Result) override;
+  void CompleteType(TagDecl *Tag) override;
+  void CompleteType(ObjCInterfaceDecl *Class) override;
+  void StartedDeserializing() override;
+  void FinishedDeserializing() override;
+  void StartTranslationUnit(ASTConsumer *Consumer) override;
+  void PrintStats() override;
+
+  /// Return the amount of memory used by memory buffers, breaking down
+  /// by heap-backed versus mmap'ed memory.
+  void getMemoryBufferSizes(MemoryBufferSizes &sizes) const override;
+
+  //===----------------------------------------------------------------------===//
+  // ExternalSemaSource interface.
+  //===----------------------------------------------------------------------===//
+
+  void InitializeSema(Sema &S) override;
+  void ForgetSema() override;
+  void ReadMethodPool(Selector Sel) override;
+  bool LookupUnqualified(LookupResult &R, Scope *S) override;
+};
+}
+
 static ASTReader *
 createASTReader(CompilerInstance &CI, StringRef pchFile,
                 SmallVectorImpl<llvm::MemoryBuffer *> &memBufs,
@@ -62,8 +109,8 @@ ChainedIncludesSource::~ChainedIncludesSource() {
     delete CIs[i];
 }
 
-IntrusiveRefCntPtr<ChainedIncludesSource>
-ChainedIncludesSource::create(CompilerInstance &CI) {
+IntrusiveRefCntPtr<ExternalSemaSource> clang::createChainedIncludesSource(
+    CompilerInstance &CI, IntrusiveRefCntPtr<ExternalSemaSource> &Reader) {
 
   std::vector<std::string> &includes = CI.getPreprocessorOpts().ChainedIncludes;
   assert(!includes.empty() && "No '-chain-include' in options!");
@@ -156,7 +203,6 @@ ChainedIncludesSource::create(CompilerInstance &CI) {
   assert(!serialBufs.empty());
   std::string pchName = includes.back() + ".pch-final";
   serialBufNames.push_back(pchName);
-  IntrusiveRefCntPtr<ASTReader> Reader;
   Reader = createASTReader(CI, pchName, serialBufs, serialBufNames);
   if (!Reader)
     return nullptr;
diff --git a/clang/lib/Frontend/FrontendAction.cpp b/clang/lib/Frontend/FrontendAction.cpp
index 1cf4a79fd2f4..c274ba71768c 100644
--- a/clang/lib/Frontend/FrontendAction.cpp
+++ b/clang/lib/Frontend/FrontendAction.cpp
@@ -12,7 +12,6 @@
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/DeclGroup.h"
 #include "clang/Frontend/ASTUnit.h"
-#include "clang/Frontend/ChainedIncludesSource.h"
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/Frontend/FrontendDiagnostic.h"
 #include "clang/Frontend/FrontendPluginRegistry.h"
@@ -315,13 +314,12 @@ bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
     
     if (!CI.getPreprocessorOpts().ChainedIncludes.empty()) {
       // Convert headers to PCH and chain them.
-      IntrusiveRefCntPtr<ChainedIncludesSource> source;
-      source = ChainedIncludesSource::create(CI);
+      IntrusiveRefCntPtr<ExternalSemaSource> source, FinalReader;
+      source = createChainedIncludesSource(CI, FinalReader);
       if (!source)
         goto failure;
-      CI.setModuleManager(static_cast<ASTReader*>(&source->getFinalReader()));
+      CI.setModuleManager(static_cast<ASTReader *>(FinalReader.get()));
       CI.getASTContext().setExternalSource(source);
-
     } else if (!CI.getPreprocessorOpts().ImplicitPCHInclude.empty()) {
       // Use PCH.
       assert(hasPCHSupport() && "This action does not have PCH support!");