INPUT element: Do not update selectionStart/selectionEnd on |value| IDL setter if the new value is …

third_party/WebKit/Source/core/html/HTMLTextAreaElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 Apple Inc. All rights
  * reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2007 Samuel Weinig (sam@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 380 matching lines @@
     const String& new_value,
     TextFieldEventBehavior event_behavior,
     TextControlSetValueSelection selection) {
   // Code elsewhere normalizes line endings added by the user via the keyboard
   // or pasting.  We normalize line endings coming from JavaScript here.
   String normalized_value = new_value.IsNull() ? "" : new_value;
   normalized_value.Replace("\r\n", "\n");
   normalized_value.Replace('\r', '\n');
 
   // Return early because we don't want to trigger other side effects when the
-  // value isn't changing. This is interoperable though the specification
-  // doesn't define so.
-  // https://github.com/whatwg/html/issues/2412
+  // value isn't changing. This is interoperable.
   if (normalized_value == value())
     return;
 
   if (event_behavior != kDispatchNoEvent)
     SetValueBeforeFirstUserEditIfNotSet();
   value_ = normalized_value;
   SetInnerEditorValue(value_);
   if (event_behavior == kDispatchNoEvent)
     SetLastChangeWasNotUserEdit();
   else
@@ skipping 218 matching lines @@
     const Element& source) {
   const HTMLTextAreaElement& source_element =
       static_cast<const HTMLTextAreaElement&>(source);
   SetValueCommon(source_element.value(), kDispatchNoEvent,
                  TextControlSetValueSelection::kSetSelectionToEnd);
   is_dirty_ = source_element.is_dirty_;
   TextControlElement::CopyNonAttributePropertiesFromElement(source);
 }
 
 }  // namespace blink