Avoid adding placeholder when deleting last text in root

Source/core/html/HTMLInputElement.cpp

Index: Source/core/html/HTMLInputElement.cpp
diff --git a/Source/core/html/HTMLInputElement.cpp b/Source/core/html/HTMLInputElement.cpp
index 315c4b93e67247cacfb2357dc8cfde8bfe6b718c..5983d417c03b3c4e9a14ec5dcd650b3c6d441442 100644
--- a/Source/core/html/HTMLInputElement.cpp
+++ b/Source/core/html/HTMLInputElement.cpp
@@ -1053,10 +1053,7 @@ void HTMLInputElement::setValueFromRenderer(const String& value)
     // Renderer and our event handler are responsible for sanitizing values.
     ASSERT(value == sanitizeValue(value) || sanitizeValue(value).isEmpty());
 
-    // Workaround for bug where trailing \n is included in the result of textContent.
-    // The assert macro above may also be simplified to: value == constrainValue(value)
-    // http://bugs.webkit.org/show_bug.cgi?id=9661
-    m_valueIfDirty = value == "\n" ? emptyString() : value;
+    m_valueIfDirty = value;
 
     setFormControlValueMatchesRenderer(true);
     m_wasModifiedByUser = true;