Introduce InsertIncrementalTextCommand to respect existing style for composition

third_party/WebKit/Source/core/editing/InputMethodController.h

Index: third_party/WebKit/Source/core/editing/InputMethodController.h
diff --git a/third_party/WebKit/Source/core/editing/InputMethodController.h b/third_party/WebKit/Source/core/editing/InputMethodController.h
index b2b59b5f9cf600412f5baafb39bcec872bb84136..ce816507de82db2924f10904145fec6eb0e2ba92 100644
--- a/third_party/WebKit/Source/core/editing/InputMethodController.h
+++ b/third_party/WebKit/Source/core/editing/InputMethodController.h
@@ -110,7 +110,6 @@ class CORE_EXPORT InputMethodController final
 
   Member<LocalFrame> m_frame;
   Member<Range> m_compositionRange;
-  bool m_isDirty;
   bool m_hasComposition;
 
   explicit InputMethodController(LocalFrame&);
@@ -143,10 +142,6 @@ class CORE_EXPORT InputMethodController final
   PlainTextRange createSelectionRangeForSetComposition(int selectionStart,
                                                        int selectionEnd,
                                                        size_t textLength) const;
-  void setCompositionWithIncrementalText(const String&,
-                                         const Vector<CompositionUnderline>&,
-                                         int selectionStart,
-                                         int selectionEnd);
   int textInputFlags() const;
   WebTextInputMode inputModeOfFocusedElement() const;