(Re-)introduce AncestorThrottle to handle 'X-Frame-Options'.

chrome/renderer/chrome_content_renderer_client.cc

 // 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.
 
 #include "chrome/renderer/chrome_content_renderer_client.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/command_line.h"
@@ skipping 996 matching lines @@
 bool ChromeContentRendererClient::ShouldSuppressErrorPage(
     content::RenderFrame* render_frame,
     const GURL& url) {
   // Unit tests for ChromeContentRendererClient pass a NULL RenderFrame here.
   // Unfortunately it's very difficult to construct a mock RenderView, so skip
   // this functionality in this case.
   if (render_frame &&
       NetErrorHelper::Get(render_frame)->ShouldSuppressErrorPage(url)) {
     return true;
   }
+
+#if defined(ENABLE_EXTENSIONS)
+  // Suppress error pages for the webstore when it's loaded in a frame. This
+  // mitigates confusion which could arise from the fact that error pages commit
+  // with the same URL as the failed load. Since pieces of the browser sometimes
+  // rely on the last-committed URL as a permission check of sorts, and the
+  // webstore is a special flower, this can cause problems that we can avoid by
+  // simply suppressing the error page (see https://crbug.com/622385, for
+  // example).
+  GURL webstore_url(extension_urls::GetWebstoreLaunchURL());
+  if (!render_frame->IsMainFrame() && url.SchemeIsHTTPOrHTTPS() &&
+      url.DomainIs(webstore_url.host().c_str())) {
+    return true;
+  }
+#endif
+
   // Do not flash an error page if the Instant new tab page fails to load.
   return SearchBouncer::GetInstance()->IsNewTabPage(url);
 }
 
 void ChromeContentRendererClient::GetNavigationErrorStrings(
     content::RenderFrame* render_frame,
     const WebURLRequest& failed_request,
     const WebURLError& error,
     std::string* error_html,
     base::string16* error_description) {
@@ skipping 456 matching lines @@
 
   url::Replacements<char> r;
   r.SetPath(path.c_str(), url::Component(0, path.length()));
 
   if (result == internal::NUM_PLUGIN_ERROR)
     result = invalid_url ? internal::SUCCESS_PARAMS_REWRITE : internal::SUCCESS;
 
   RecordYouTubeRewriteUMA(result);
   return corrected_url.ReplaceComponents(r);
 }