[Editing] Introduce |EditCommandComposition::willUn/Reapply()| in prepare for 'beforeinput' (2/3)

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 9cdbada94423cfaf763554b716e6c9e8e4a6ff5e..f89011a85f3db41d8779cecb033b7a71e1087d6e 100644
--- a/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.h
+++ b/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.h
@@ -52,8 +52,8 @@ class EditCommandComposition final : public UndoStep {
                                         InputEvent::InputType);
 
   bool belongsTo(const LocalFrame&) const override;
-  void unapply() override;
-  void reapply() override;
+  void unapply(EditCommandSource) override;
+  void reapply(EditCommandSource) override;
   InputEvent::InputType inputType() const override;
   void append(SimpleEditCommand*);
   void append(EditCommandComposition*);
@@ -79,6 +79,13 @@ class EditCommandComposition final : public UndoStep {
                          const VisibleSelection& endingSelection,
                          InputEvent::InputType);
 
+  // Fires "beforeinput". Returns |false| to cancel unapply / reapply when

[Xiaocheng, 2016/12/19 03:43:00]

Please add a "TODO: implementation" note that the two functions are not really
firing beforeinput for now.

[chongz, 2016/12/19 20:56:24]

Done.

+  //   * "beforeinput" was canceled, or
+  //   * |frame| was destroyed by event handlers.
+  // Note: Undo stack will always get popped.
+  bool willUnapply(EditCommandSource);
+  bool willReapply(EditCommandSource);
+
   Member<Document> m_document;
   VisibleSelection m_startingSelection;
   VisibleSelection m_endingSelection;