Enable shadow DOM-based "missing plugin" placeholder.

chrome/renderer/chrome_content_renderer_client.h

 // Copyright (c) 2012 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_CHROME_CONTENT_RENDERER_CLIENT_H_
 #define CHROME_RENDERER_CHROME_CONTENT_RENDERER_CLIENT_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 67 matching lines @@
   void RenderThreadStarted() override;
   void RenderFrameCreated(content::RenderFrame* render_frame) override;
   void RenderViewCreated(content::RenderView* render_view) override;
   void SetNumberOfViews(int number_of_views) override;
   SkBitmap* GetSadPluginBitmap() override;
   SkBitmap* GetSadWebViewBitmap() override;
   bool OverrideCreatePlugin(content::RenderFrame* render_frame,
                             blink::WebLocalFrame* frame,
                             const blink::WebPluginParams& params,
                             blink::WebPlugin** plugin) override;
+  blink::WebPluginPlaceholder* OverrideCreatePluginPlaceholder(
+      content::RenderFrame* render_frame,
+      blink::WebLocalFrame* frame,
+      const blink::WebPluginParams& params) override;
   blink::WebPlugin* CreatePluginReplacement(
       content::RenderFrame* render_frame,
       const base::FilePath& plugin_path) override;
   bool HasErrorPage(int http_status_code, std::string* error_domain) override;
   bool ShouldSuppressErrorPage(content::RenderFrame* render_frame,
                                const GURL& url) override;
   void GetNavigationErrorStrings(content::RenderView* render_view,
                                  blink::WebFrame* frame,
                                  const blink::WebURLRequest& failed_request,
                                  const blink::WebURLError& error,
@@ skipping 132 matching lines @@
 #if defined(ENABLE_FULL_PRINTING)
   scoped_ptr<ChromePDFPrintClient> pdf_print_client_;
 #endif
 #if defined(ENABLE_PLUGINS)
   std::set<std::string> allowed_compositor_origins_;
   std::set<std::string> allowed_video_decode_origins_;
 #endif
 };
 
 #endif  // CHROME_RENDERER_CHROME_CONTENT_RENDERER_CLIENT_H_