[Editing] Introduce |CompositeEditCommand::willApplyEditing()| in prepare for 'beforeinput' (1/3)

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 f2d7317eeca7d2291063530eaefa637e55976300..9cdbada94423cfaf763554b716e6c9e8e4a6ff5e 100644
--- a/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.h
+++ b/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.h
@@ -118,6 +118,14 @@ class CORE_EXPORT CompositeEditCommand : public EditCommand {
  protected:
   explicit CompositeEditCommand(Document&);
 
+  // Fires "beforeinput", returns |false| to cancel applying editing if
+  //   * "beforeinput" was canceled, or
+  //   * |frame| was destroyed by event handlers.
+  // |willApplyEditing()| should be called from
+  //   * |CompositeEditCommand::willApply()|, and
+  //   * |TypingCommand::willAddTypingToOpenCommand()|.
+  bool willApplyEditing(EditCommandSource);

[Xiaocheng, 2016/12/19 03:33:57]

Please add a TODO: implementation note here since this function is not really
firing beforeinput for now.

[chongz, 2016/12/19 06:48:57]

Will do.

[chongz, 2016/12/19 20:55:22]

Done.

+
   //
   // sugary-sweet convenience functions to help create and apply edit commands
   // in composite commands
@@ -265,6 +273,9 @@ class CORE_EXPORT CompositeEditCommand : public EditCommand {
   HeapVector<Member<EditCommand>> m_commands;
 
  private:
+  // Returns |false| to cancel applying command.
+  bool willApply(EditCommandSource);
+
   bool isCompositeEditCommand() const final { return true; }
 
   Member<EditCommandComposition> m_composition;