Plugin Placeholders: Refactor for platforms that don't support plugins

components/plugins/renderer/webview_plugin.cc

 // Copyright 2013 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.
 
 #include "components/plugins/renderer/webview_plugin.h"
 
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/numerics/safe_conversions.h"
 #include "content/public/common/web_preferences.h"
@@ skipping 43 matching lines @@
   content::RenderView::ApplyWebPreferences(preferences, web_view_);
   web_frame_ = WebLocalFrame::create(blink::WebTreeScopeType::Document, this);
   web_view_->setMainFrame(web_frame_);
 }
 
 // static
 WebViewPlugin* WebViewPlugin::Create(WebViewPlugin::Delegate* delegate,
                                      const WebPreferences& preferences,
                                      const std::string& html_data,
                                      const GURL& url) {
+  DCHECK(url.is_valid()) << "Blink requires the WebView to have a valid URL.";
   WebViewPlugin* plugin = new WebViewPlugin(delegate, preferences);
   plugin->web_view()->mainFrame()->loadHTMLString(html_data, url);
   return plugin;
 }
 
 WebViewPlugin::~WebViewPlugin() {
   web_view_->close();
   web_frame_->close();
 }
 
@@ skipping 189 matching lines @@
 void WebViewPlugin::didClearWindowObject(WebLocalFrame* frame) {
   if (delegate_)
     delegate_->BindWebFrame(frame);
 }
 
 void WebViewPlugin::didReceiveResponse(WebLocalFrame* frame,
                                        unsigned identifier,
                                        const WebURLResponse& response) {
   WebFrameClient::didReceiveResponse(frame, identifier, response);
 }