Fix loading success.html at the end of chrome://chrome-signin flow

extensions/browser/url_request_util.cc

 // 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.
 
 #include "extensions/browser/url_request_util.h"
 
 #include <string>
 
 #include "content/public/browser/resource_request_info.h"
 #include "content/public/common/browser_side_navigation_policy.h"
@@ skipping 135 matching lines @@
 }
 
 bool AllowCrossRendererResourceLoadHelper(bool is_guest,
                                           const Extension* extension,
                                           const Extension* owner_extension,
                                           const std::string& partition_id,
                                           const std::string& resource_path,
                                           ui::PageTransition page_transition,
                                           bool* allowed) {
   if (is_guest) {
+    // Exceptionally, the resource at path "/success.html" that belongs to the
+    // sign-in extension (loaded by chrome://chrome-signin) is accessible to
+    // WebViews that are not owned by that extension.
+    // This exception is required as in order to mark the end of the the sign-in
+    // flow, Gaia redirects to the following continue URL:
+    // "chrome-extension://mfffpogegjflfpflabcdkioaeobkgjik/success.html".
+    //
+    // TODO(http://crbug.com/688565) Remove this check once the sign-in
+    // extension is deprecated and removed.
+    bool is_signin_extension =
+        extension && extension->id() == "mfffpogegjflfpflabcdkioaeobkgjik";
+    if (is_signin_extension && resource_path == "/success.html") {
+      *allowed = true;
+      return true;
+    }
+
     // An extension's resources should only be accessible to WebViews owned by
     // that extension.
     if (owner_extension != extension) {
       *allowed = false;
       return true;
     }
 
     *allowed = WebviewInfo::IsResourceWebviewAccessible(extension, partition_id,
                                                         resource_path);
     return true;
   }
 
   return false;
 }
 
 }  // namespace url_request_util
 }  // namespace extensions