Hide textarea placeholder text when showing autofill suggestion

Source/core/html/HTMLTextAreaElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2010 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 63 matching lines @@
     void handleBeforeTextInsertedEvent(BeforeTextInsertedEvent*) const;
     static String sanitizeUserInputValue(const String&, unsigned maxLength);
     void updateValue() const;
     virtual void setInnerTextValue(const String&) OVERRIDE;
     void setNonDirtyValue(const String&);
     void setValueCommon(const String&, TextFieldEventBehavior);
 
     virtual bool supportsPlaceholder() const OVERRIDE { return true; }
     virtual void updatePlaceholderText() OVERRIDE;
     virtual bool isEmptyValue() const OVERRIDE { return value().isEmpty(); }
+    virtual bool isEmptySuggestedValue() const OVERRIDE FINAL { return suggestedValue().isEmpty(); }
 
     virtual bool isOptionalFormControl() const OVERRIDE { return !isRequiredFormControl(); }
     virtual bool isRequiredFormControl() const OVERRIDE { return isRequired(); }
 
     virtual void defaultEventHandler(Event*) OVERRIDE;
     virtual void handleFocusEvent(Element* oldFocusedNode, FocusType) OVERRIDE;
 
     virtual void subtreeHasChanged() OVERRIDE;
 
     virtual bool isEnumeratable() const OVERRIDE { return true; }
@@ skipping 34 matching lines @@
     WrapMethod m_wrap;
     mutable String m_value;
     mutable bool m_isDirty;
     bool m_valueIsUpToDate;
     String m_suggestedValue;
 };
 
 } //namespace
 
 #endif