Merge NativeTextfieldViews into views::Textfield.

ui/views/controls/textfield/textfield_views_model.cc

Index: ui/views/controls/textfield/textfield_views_model.cc
diff --git a/ui/views/controls/textfield/textfield_views_model.cc b/ui/views/controls/textfield/textfield_views_model.cc
index 6179e8fda3d8c7362f9387c7ea292022a914c7de..937ccb6fc676639fad45987b6d53656189155a57 100644
--- a/ui/views/controls/textfield/textfield_views_model.cc
+++ b/ui/views/controls/textfield/textfield_views_model.cc
@@ -652,6 +652,11 @@ bool TextfieldViewsModel::HasCompositionText() const {
   return !render_text_->GetCompositionRange().is_empty();
 }
 
+void TextfieldViewsModel::ClearEditHistory() {
+  STLDeleteElements(&edit_history_);
+  current_edit_ = edit_history_.end();
+}
+
 /////////////////////////////////////////////////////////////////
 // TextfieldViewsModel: private
 
@@ -688,11 +693,6 @@ void TextfieldViewsModel::ReplaceTextInternal(const base::string16& text,
   InsertTextInternal(text, mergeable);
 }
 
-void TextfieldViewsModel::ClearEditHistory() {
-  STLDeleteElements(&edit_history_);
-  current_edit_ = edit_history_.end();
-}
-
 void TextfieldViewsModel::ClearRedoHistory() {
   if (edit_history_.begin() == edit_history_.end())
     return;