[InputEvent] Support |deleteByDrag|, |insertFromDrop| and fire in sequential order

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

Index: third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.h
diff --git a/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.h b/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.h
index e0045ec255bcfdb51e3a37fbca42af6298f0d7d2..4226bbfce7f34a1a2bceb4ebd11b3cb6154a07e9 100644
--- a/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.h
+++ b/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.h
@@ -54,6 +54,7 @@ class EditCommandComposition final : public UndoStep {
   void reapply() override;
   InputEvent::InputType inputType() const override;
   void append(SimpleEditCommand*);
+  void append(EditCommandComposition*);
 
   const VisibleSelection& startingSelection() const {
     return m_startingSelection;
@@ -99,9 +100,13 @@ class CORE_EXPORT CompositeEditCommand : public EditCommand {
   }
   EditCommandComposition* composition() { return m_composition.get(); }
   EditCommandComposition* ensureComposition();
+  // Append composition from an already applied command.
+  void appendCommandToComposite(CompositeEditCommand*);
 
   virtual bool isReplaceSelectionCommand() const;
   virtual bool isTypingCommand() const;
+  virtual bool isCommandGroupWrapper() const;
+  virtual bool isDragAndDropCommand() const;
   virtual bool preservesTypingStyle() const;
   virtual void setShouldRetainAutocorrectionIndicator(bool);
   virtual bool shouldStopCaretBlinking() const { return false; }