Plugins: Remove Shadow DOM Plugin Placeholder

chrome/renderer/plugins/shadow_dom_plugin_placeholder.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 CHROME_RENDERER_PLUGINS_SHADOW_DOM_PLUGIN_PLACEHOLDER_H_
-#define CHROME_RENDERER_PLUGINS_SHADOW_DOM_PLUGIN_PLACEHOLDER_H_
-
-#include "base/memory/scoped_ptr.h"
-#include "third_party/WebKit/public/web/WebPluginPlaceholder.h"
-
-namespace blink {
-class WebLocalFrame;
-struct WebPluginParams;
-}
-
-namespace content {
-class RenderFrame;
-}
-
-// This is the Chrome implementation of shadow DOM plugin placeholders,
-// intended to ultimately replace those based on WebViewPlugin.
-// It is guarded by the --enable-plugin-placeholder-shadow-dom switch.
-
-// Returns |true| if shadow DOM plugin placeholders are enabled.
-bool ShadowDOMPluginPlaceholderEnabled();
-
-// Possibly creates a placeholder given plugin info output.
-// Returns nullptr if it is not appropriate to create a placeholder
-// (for instance, because the plugin should be allowed to load).
-scoped_ptr<blink::WebPluginPlaceholder> CreateShadowDOMPlaceholderForPluginInfo(
-    content::RenderFrame* render_frame,
-    blink::WebLocalFrame* frame,
-    const blink::WebPluginParams& orig_params);
-
-// Creates a placeholder suitable for representing a missing plugin.
-scoped_ptr<blink::WebPluginPlaceholder>
-CreateShadowDOMPlaceholderForMissingPlugin();
-
-#endif  // CHROME_RENDERER_PLUGINS_SHADOW_DOM_PLUGIN_PLACEHOLDER_H_