Rename class EditCommandComposition to UndoStep

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

Index: third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.cpp
diff --git a/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.cpp b/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.cpp
index 4f79038db86e058eb80e5fcaa754c2dbfc906968..ce3d8711efe5bb97685619c804c8ba8146e2ddb9 100644
--- a/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.cpp
+++ b/third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.cpp
@@ -138,13 +138,14 @@ bool CompositeEditCommand::apply() {
   return !editingState.isAborted();
 }
 
-EditCommandComposition* CompositeEditCommand::ensureComposition() {
+UndoStep* CompositeEditCommand::ensureComposition() {
   CompositeEditCommand* command = this;
   while (command && command->parent())
     command = command->parent();
-  if (!command->m_composition)
-    command->m_composition = EditCommandComposition::create(
-        &document(), startingSelection(), endingSelection(), inputType());
+  if (!command->m_composition) {
+    command->m_composition = UndoStep::create(&document(), startingSelection(),
+                                              endingSelection(), inputType());
+  }
   return command->m_composition.get();
 }