Implement support for closing shadow DOM plugin placeholders.

Source/core/plugins/testing/DictionaryPluginPlaceholder.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef DictionaryPluginPlaceholder_h
 #define DictionaryPluginPlaceholder_h
 
 #include "bindings/core/v8/Dictionary.h"
 #include "core/html/shadow/PluginPlaceholderElement.h"
 #include "core/plugins/PluginPlaceholder.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 // Manipulates a plugin placeholder element based on a fixed dictionary given.
 // Used for layout tests that examine the formatting of structured placeholders.
 class DictionaryPluginPlaceholder : public NoBaseWillBeGarbageCollected<DictionaryPluginPlaceholder>, public PluginPlaceholder {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(DictionaryPluginPlaceholder);
 public:
     static PassOwnPtrWillBeRawPtr<DictionaryPluginPlaceholder> create(Document& document, const Dictionary& options)
     {
         RefPtrWillBeRawPtr<PluginPlaceholderElement> placeholder = PluginPlaceholderElement::create(document);
         String stringValue;
         if (DictionaryHelper::get(options, "message", stringValue))
             placeholder->setMessage(stringValue);
 
+        bool booleanValue;
+        if (DictionaryHelper::get(options, "closeable", booleanValue))
+            placeholder->setIsCloseable(booleanValue);
+
         return adoptPtrWillBeNoop(new DictionaryPluginPlaceholder(placeholder.release()));
     }
 
 #if !ENABLE(OILPAN)
     virtual ~DictionaryPluginPlaceholder() override { }
 #endif
     virtual void trace(Visitor* visitor) { visitor->trace(m_pluginPlaceholderElement); }
 
     virtual void loadIntoContainer(ContainerNode& container) override
     {
         container.removeChildren();
         container.appendChild(m_pluginPlaceholderElement, ASSERT_NO_EXCEPTION);
     }
 
 private:
     DictionaryPluginPlaceholder(PassRefPtrWillBeRawPtr<PluginPlaceholderElement> element) : m_pluginPlaceholderElement(element) { }
 
     RefPtrWillBeMember<PluginPlaceholderElement> m_pluginPlaceholderElement;
 };
 
 } // namespace blink
 
 #endif // DictionaryPluginPlaceholder_h