Add support for retrieving image thumbnails as part of the accessibility tree.

third_party/WebKit/Source/web/WebAXObject.cpp

 /*
  * Copyright (C) 2009 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 590 matching lines @@
   return m_private->fontSize();
 }
 
 bool WebAXObject::canvasHasFallbackContent() const {
   if (isDetached())
     return false;
 
   return m_private->canvasHasFallbackContent();
 }
 
+WebString WebAXObject::imageDataUrl(const WebSize& maxSize) const {
+  if (isDetached())
+    return WebString();
+
+  return m_private->imageDataUrl(maxSize);
+}
+
 WebAXInvalidState WebAXObject::invalidState() const {
   if (isDetached())
     return WebAXInvalidStateUndefined;
 
   return static_cast<WebAXInvalidState>(m_private->getInvalidState());
 }
 
 // Only used when invalidState() returns WebAXInvalidStateOther.
 WebString WebAXObject::ariaInvalidValue() const {
   if (isDetached())
@@ skipping 842 matching lines @@
 WebAXObject& WebAXObject::operator=(AXObject* object) {
   m_private = object;
   return *this;
 }
 
 WebAXObject::operator AXObject*() const {
   return m_private.get();
 }
 
 }  // namespace blink