Introduce InsertIncrementalTextCommand to respect existing style for composition

third_party/WebKit/Source/core/editing/commands/TypingCommand.h

Index: third_party/WebKit/Source/core/editing/commands/TypingCommand.h
diff --git a/third_party/WebKit/Source/core/editing/commands/TypingCommand.h b/third_party/WebKit/Source/core/editing/commands/TypingCommand.h
index a21fa5177dcd6d12499e2e05e337499d259e7812..437980a51dff5c2ea4705dba5428aa8813a8091e 100644
--- a/third_party/WebKit/Source/core/editing/commands/TypingCommand.h
+++ b/third_party/WebKit/Source/core/editing/commands/TypingCommand.h
@@ -69,12 +69,14 @@ class CORE_EXPORT TypingCommand final : public CompositeEditCommand {
   static void insertText(Document&,
                          const String&,
                          Options,
-                         TextCompositionType = TextCompositionNone);
+                         TextCompositionType = TextCompositionNone,
+                         const bool isIncrementalInsertion = false);
   static void insertText(Document&,
                          const String&,
                          const VisibleSelection&,
                          Options,
-                         TextCompositionType = TextCompositionNone);
+                         TextCompositionType = TextCompositionNone,
+                         const bool isIncrementalInsertion = false);
   static bool insertLineBreak(Document&);
   static bool insertParagraphSeparator(Document&);
   static bool insertParagraphSeparatorInQuotedContent(Document&);
@@ -93,6 +95,10 @@ class CORE_EXPORT TypingCommand final : public CompositeEditCommand {
   void setCompositionType(TextCompositionType type) {
     m_compositionType = type;
   }
+  static void adjustSelectionAfterIncrementalInsertion(TypingCommand*,
+                                                       LocalFrame*,
+                                                       const size_t start,
+                                                       const size_t end);
 
   ETypingCommand commandTypeOfOpenCommand() const { return m_commandType; }
   TextCompositionType compositionType() const { return m_compositionType; }
@@ -156,6 +162,8 @@ class CORE_EXPORT TypingCommand final : public CompositeEditCommand {
     m_commandType = typingCommand;
   }
 
+  bool isIncrementalInsertion() const { return m_isIncrementalInsertion; }
+
   ETypingCommand m_commandType;
   String m_textToInsert;
   bool m_openForMoreTyping;
@@ -173,6 +181,8 @@ class CORE_EXPORT TypingCommand final : public CompositeEditCommand {
 
   bool m_shouldRetainAutocorrectionIndicator;
   bool m_shouldPreventSpellChecking;
+
+  bool m_isIncrementalInsertion;
 };
 
 DEFINE_TYPE_CASTS(TypingCommand,