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

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

Index: third_party/WebKit/Source/core/editing/commands/UndoStep.h
diff --git a/third_party/WebKit/Source/core/editing/commands/UndoStep.h b/third_party/WebKit/Source/core/editing/commands/UndoStep.h
index 08011f069750dd2089baff2d92563093ac1a74c6..4aa768978e4bf149ce539dc85ebfd7fdee6d256e 100644
--- a/third_party/WebKit/Source/core/editing/commands/UndoStep.h
+++ b/third_party/WebKit/Source/core/editing/commands/UndoStep.h
@@ -36,7 +36,6 @@
 
 namespace blink {
 
-enum class EditCommandSource;
 class LocalFrame;
 
 class UndoStep : public GarbageCollectedFinalized<UndoStep> {
@@ -45,8 +44,8 @@
   DEFINE_INLINE_VIRTUAL_TRACE() {}
 
   virtual bool belongsTo(const LocalFrame&) const = 0;
-  virtual void unapply(EditCommandSource) = 0;
-  virtual void reapply(EditCommandSource) = 0;
+  virtual void unapply() = 0;
+  virtual void reapply() = 0;
   virtual InputEvent::InputType inputType() const = 0;
 };