Add autofill preview support for Textarea

Source/core/testing/Internals.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 1001 matching lines @@
     return false;
 }
 
 String Internals::suggestedValue(Element* element, ExceptionState& exceptionState)
 {
     if (!element) {
         exceptionState.throwUninformativeAndGenericDOMException(InvalidAccessError);
         return String();
     }
 
-    if (!element->hasTagName(inputTag)) {
+    if (!element->isFormControlElement()) {
         exceptionState.throwUninformativeAndGenericDOMException(InvalidNodeTypeError);
         return String();
     }
 
-    return toHTMLInputElement(element)->suggestedValue();
+    String suggestedValue;
+    if (element->hasTagName(inputTag))
+        suggestedValue = toHTMLInputElement(element)->suggestedValue();
+
+    if (element->hasTagName(textareaTag))
+        suggestedValue = toHTMLTextAreaElement(element)->suggestedValue();
+    return suggestedValue;
 }
 
 void Internals::setSuggestedValue(Element* element, const String& value, ExceptionState& exceptionState)
 {
     if (!element) {
         exceptionState.throwUninformativeAndGenericDOMException(InvalidAccessError);
         return;
     }
 
-    if (!element->hasTagName(inputTag)) {
+    if (!element->isFormControlElement()) {
         exceptionState.throwUninformativeAndGenericDOMException(InvalidNodeTypeError);
         return;
     }
 
-    toHTMLInputElement(element)->setSuggestedValue(value);
+    if (element->hasTagName(inputTag))
+        toHTMLInputElement(element)->setSuggestedValue(value);
+
+    if (element->hasTagName(textareaTag))
+        toHTMLTextAreaElement(element)->setSuggestedValue(value);
 }
 
 void Internals::setEditingValue(Element* element, const String& value, ExceptionState& exceptionState)
 {
     if (!element) {
         exceptionState.throwUninformativeAndGenericDOMException(InvalidAccessError);
         return;
     }
 
     if (!element->hasTagName(inputTag)) {
@@ skipping 1275 matching lines @@
     if (view->compositor())
         view->compositor()->updateCompositingLayers(CompositingUpdateFinishAllDeferredWork);
 }
 
 void Internals::setZoomFactor(float factor)
 {
     frame()->setPageZoomFactor(factor);
 }
 
 }