diff --git a/clang/lib/Tooling/Refactoring/AtomicChange.cpp b/clang/lib/Tooling/Refactoring/AtomicChange.cpp
index 79dd346..082bf59 100644
--- a/clang/lib/Tooling/Refactoring/AtomicChange.cpp
+++ b/clang/lib/Tooling/Refactoring/AtomicChange.cpp
@@ -83,6 +83,116 @@
 
 namespace clang {
 namespace tooling {
+namespace {
+
+// Returns true if there is any line that violates \p ColumnLimit in range
+// [Start, End].
+bool violatesColumnLimit(llvm::StringRef Code, unsigned ColumnLimit,
+                         unsigned Start, unsigned End) {
+  auto StartPos = Code.rfind('\n', Start);
+  StartPos = (StartPos == llvm::StringRef::npos) ? 0 : StartPos + 1;
+
+  auto EndPos = Code.find("\n", End);
+  if (EndPos == llvm::StringRef::npos)
+    EndPos = Code.size();
+
+  llvm::SmallVector<llvm::StringRef, 8> Lines;
+  Code.substr(StartPos, EndPos - StartPos).split(Lines, '\n');
+  for (llvm::StringRef Line : Lines)
+    if (Line.size() > ColumnLimit)
+      return true;
+  return false;
+}
+
+std::vector<Range>
+getRangesForFormating(llvm::StringRef Code, unsigned ColumnLimit,
+                      ApplyChangesSpec::FormatOption Format,
+                      const clang::tooling::Replacements &Replaces) {
+  // kNone suppresses formatting entirely.
+  if (Format == ApplyChangesSpec::kNone)
+    return {};
+  std::vector<clang::tooling::Range> Ranges;
+  // This works assuming that replacements are ordered by offset.
+  // FIXME: use `getAffectedRanges()` to calculate when it does not include '\n'
+  // at the end of an insertion in affected ranges.
+  int Offset = 0;
+  for (const clang::tooling::Replacement &R : Replaces) {
+    int Start = R.getOffset() + Offset;
+    int End = Start + R.getReplacementText().size();
+    if (!R.getReplacementText().empty() &&
+        R.getReplacementText().back() == '\n' && R.getLength() == 0 &&
+        R.getOffset() > 0 && R.getOffset() <= Code.size() &&
+        Code[R.getOffset() - 1] == '\n')
+      // If we are inserting at the start of a line and the replacement ends in
+      // a newline, we don't need to format the subsequent line.
+      --End;
+    Offset += R.getReplacementText().size() - R.getLength();
+
+    if (Format == ApplyChangesSpec::kAll ||
+        violatesColumnLimit(Code, ColumnLimit, Start, End))
+      Ranges.emplace_back(Start, End - Start);
+  }
+  return Ranges;
+}
+
+inline llvm::Error make_string_error(const llvm::Twine &Message) {
+  return llvm::make_error<llvm::StringError>(Message,
+                                             llvm::inconvertibleErrorCode());
+}
+
+// Creates replacements for inserting/deleting #include headers.
+llvm::Expected<Replacements>
+createReplacementsForHeaders(llvm::StringRef FilePath, llvm::StringRef Code,
+                             llvm::ArrayRef<AtomicChange> Changes,
+                             const format::FormatStyle &Style) {
+  // Create header insertion/deletion replacements to be cleaned up
+  // (i.e. converted to real insertion/deletion replacements).
+  Replacements HeaderReplacements;
+  for (const auto &Change : Changes) {
+    for (llvm::StringRef Header : Change.getInsertedHeaders()) {
+      std::string EscapedHeader =
+          Header.startswith("<") || Header.startswith("\"")
+              ? Header.str()
+              : ("\"" + Header + "\"").str();
+      std::string ReplacementText = "#include " + EscapedHeader;
+      // Offset UINT_MAX and length 0 indicate that the replacement is a header
+      // insertion.
+      llvm::Error Err = HeaderReplacements.add(
+          tooling::Replacement(FilePath, UINT_MAX, 0, ReplacementText));
+      if (Err)
+        return std::move(Err);
+    }
+    for (const std::string &Header : Change.getRemovedHeaders()) {
+      // Offset UINT_MAX and length 1 indicate that the replacement is a header
+      // deletion.
+      llvm::Error Err =
+          HeaderReplacements.add(Replacement(FilePath, UINT_MAX, 1, Header));
+      if (Err)
+        return std::move(Err);
+    }
+  }
+
+  // cleanupAroundReplacements() converts header insertions/deletions into
+  // actual replacements that add/remove headers at the right location.
+  return clang::format::cleanupAroundReplacements(Code, HeaderReplacements,
+                                                  Style);
+}
+
+// Combine replacements in all Changes as a `Replacements`. This ignores the
+// file path in all replacements and replaces them with \p FilePath.
+llvm::Expected<Replacements>
+combineReplacementsInChanges(llvm::StringRef FilePath,
+                             llvm::ArrayRef<AtomicChange> Changes) {
+  Replacements Replaces;
+  for (const auto &Change : Changes)
+    for (const auto &R : Change.getReplacements())
+      if (auto Err = Replaces.add(Replacement(
+              FilePath, R.getOffset(), R.getLength(), R.getReplacementText())))
+        return std::move(Err);
+  return Replaces;
+}
+
+} // end namespace
 
 AtomicChange::AtomicChange(const SourceManager &SM,
                            SourceLocation KeyPosition) {
@@ -173,5 +283,74 @@
   RemovedHeaders.push_back(Header);
 }
 
+llvm::Expected<std::string>
+applyAtomicChanges(llvm::StringRef FilePath, llvm::StringRef Code,
+                   llvm::ArrayRef<AtomicChange> Changes,
+                   const ApplyChangesSpec &Spec) {
+  llvm::Expected<Replacements> HeaderReplacements =
+      createReplacementsForHeaders(FilePath, Code, Changes, Spec.Style);
+  if (!HeaderReplacements)
+    return make_string_error(
+        "Failed to create replacements for header changes: " +
+        llvm::toString(HeaderReplacements.takeError()));
+
+  llvm::Expected<Replacements> Replaces =
+      combineReplacementsInChanges(FilePath, Changes);
+  if (!Replaces)
+    return make_string_error("Failed to combine replacements in all changes: " +
+                             llvm::toString(Replaces.takeError()));
+
+  Replacements AllReplaces = std::move(*Replaces);
+  for (const auto &R : *HeaderReplacements) {
+    llvm::Error Err = AllReplaces.add(R);
+    if (Err)
+      return make_string_error(
+          "Failed to combine existing replacements with header replacements: " +
+          llvm::toString(std::move(Err)));
+  }
+
+  if (Spec.Cleanup) {
+    llvm::Expected<Replacements> CleanReplaces =
+        format::cleanupAroundReplacements(Code, AllReplaces, Spec.Style);
+    if (!CleanReplaces)
+      return make_string_error("Failed to cleanup around replacements: " +
+                               llvm::toString(CleanReplaces.takeError()));
+    AllReplaces = std::move(*CleanReplaces);
+  }
+
+  // Apply all replacements.
+  llvm::Expected<std::string> ChangedCode =
+      applyAllReplacements(Code, AllReplaces);
+  if (!ChangedCode)
+    return make_string_error("Failed to apply all replacements: " +
+                             llvm::toString(ChangedCode.takeError()));
+
+  // Sort inserted headers. This is done even if other formatting is turned off
+  // as incorrectly sorted headers are always just wrong, it's not a matter of
+  // taste.
+  Replacements HeaderSortingReplacements = format::sortIncludes(
+      Spec.Style, *ChangedCode, AllReplaces.getAffectedRanges(), FilePath);
+  ChangedCode = applyAllReplacements(*ChangedCode, HeaderSortingReplacements);
+  if (!ChangedCode)
+    return make_string_error(
+        "Failed to apply replacements for sorting includes: " +
+        llvm::toString(ChangedCode.takeError()));
+
+  AllReplaces = AllReplaces.merge(HeaderSortingReplacements);
+
+  std::vector<Range> FormatRanges = getRangesForFormating(
+      *ChangedCode, Spec.Style.ColumnLimit, Spec.Format, AllReplaces);
+  if (!FormatRanges.empty()) {
+    Replacements FormatReplacements =
+        format::reformat(Spec.Style, *ChangedCode, FormatRanges, FilePath);
+    ChangedCode = applyAllReplacements(*ChangedCode, FormatReplacements);
+    if (!ChangedCode)
+      return make_string_error(
+          "Failed to apply replacements for formatting changed code: " +
+          llvm::toString(ChangedCode.takeError()));
+  }
+  return ChangedCode;
+}
+
 } // end namespace tooling
 } // end namespace clang
diff --git a/clang/lib/Tooling/Refactoring/CMakeLists.txt b/clang/lib/Tooling/Refactoring/CMakeLists.txt
index 288582f..810c545 100644
--- a/clang/lib/Tooling/Refactoring/CMakeLists.txt
+++ b/clang/lib/Tooling/Refactoring/CMakeLists.txt
@@ -1,7 +1,4 @@
-set(LLVM_LINK_COMPONENTS
-  Option
-  Support
-  )
+set(LLVM_LINK_COMPONENTS Support)
 
 add_clang_library(clangToolingRefactor
   AtomicChange.cpp
@@ -14,6 +11,7 @@
   clangAST
   clangASTMatchers
   clangBasic
+  clangFormat
   clangIndex
   clangLex
   clangToolingCore