Blink Plugins: Remove Shadow DOM Plugin Placeholder

Source/core/plugins/testing/DocumentFragmentPluginPlaceholder.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 DocumentFragmentPluginPlaceholder_h
-#define DocumentFragmentPluginPlaceholder_h
-
-#include "core/dom/Document.h"
-#include "core/dom/DocumentFragment.h"
-#include "core/plugins/PluginPlaceholder.h"
-
-namespace blink {
-
-// Populates plugin placeholder content with a document fragment.
-// Used for layout tests that contain a <template>.
-class DocumentFragmentPluginPlaceholder : public NoBaseWillBeGarbageCollected<DocumentFragmentPluginPlaceholder>, public PluginPlaceholder {
-    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(DocumentFragmentPluginPlaceholder);
-public:
-    static PassOwnPtrWillBeRawPtr<DocumentFragmentPluginPlaceholder> create(PassRefPtrWillBeRawPtr<DocumentFragment> fragment)
-    {
-        return adoptPtrWillBeNoop(new DocumentFragmentPluginPlaceholder(fragment));
-    }
-
-#if !ENABLE(OILPAN)
-    ~DocumentFragmentPluginPlaceholder() override { }
-#endif
-    DEFINE_INLINE_VIRTUAL_TRACE() { visitor->trace(m_fragment); }
-
-    void loadIntoContainer(ContainerNode& container) override
-    {
-        RefPtrWillBeRawPtr<Node> clonedFragment = container.document().importNode(m_fragment.get(), true /* deep */, ASSERT_NO_EXCEPTION);
-        container.appendChild(clonedFragment.release(), ASSERT_NO_EXCEPTION);
-    }
-
-private:
-    DocumentFragmentPluginPlaceholder(PassRefPtrWillBeRawPtr<DocumentFragment> fragment) : m_fragment(fragment) { }
-
-    RefPtrWillBeMember<DocumentFragment> m_fragment;
-};
-
-} // namespace blink
-
-#endif // DocumentFragmentPluginPlaceholder_h