Clear undo stack when text control is set programatically

Source/core/html/HTMLTextFormControlElement.cpp

Index: Source/core/html/HTMLTextFormControlElement.cpp
diff --git a/Source/core/html/HTMLTextFormControlElement.cpp b/Source/core/html/HTMLTextFormControlElement.cpp
index 916142fb8104317dde9c0ad81fbbf9b799dc550a..f1083f4bb37ffabba9d11350da5260f1bbae7bdb 100644
--- a/Source/core/html/HTMLTextFormControlElement.cpp
+++ b/Source/core/html/HTMLTextFormControlElement.cpp
@@ -33,6 +33,7 @@
 #include "core/dom/NodeTraversal.h"
 #include "core/dom/Text.h"
 #include "core/dom/shadow/ShadowRoot.h"
+#include "core/editing/Editor.h"
 #include "core/editing/FrameSelection.h"
 #include "core/editing/TextIterator.h"
 #include "core/events/Event.h"
@@ -513,6 +514,9 @@ void HTMLTextFormControlElement::setInnerTextValue(const String& value)
 
         if (value.endsWith('\n') || value.endsWith('\r'))
             innerTextElement()->appendChild(HTMLBRElement::create(document()));
+
+        if (LocalFrame* frame = document().frame())
+            frame->editor().clearUndoStack();
     }
 
     setFormControlValueMatchesRenderer(true);