Remove incorrect DCHECK in RequestOpenURL.

content/browser/frame_host/navigator_impl.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 "content/browser/frame_host/navigator_impl.h"
 
 #include <utility>
 
 #include "base/metrics/histogram.h"
 #include "base/time/time.h"
@@ skipping 629 matching lines @@
   return GetContentClient()->browser()->ShouldAssignSiteForURL(url);
 }
 
 void NavigatorImpl::RequestOpenURL(RenderFrameHostImpl* render_frame_host,
                                    const GURL& url,
                                    SiteInstance* source_site_instance,
                                    const Referrer& referrer,
                                    WindowOpenDisposition disposition,
                                    bool should_replace_current_entry,
                                    bool user_gesture) {
-  // This call only makes sense for subframes if OOPIFs are possible.
-  DCHECK(!render_frame_host->GetParent() ||
-         SiteIsolationPolicy::AreCrossProcessFramesPossible());
+  // Note: This can be called for subframes (even when OOPIFs are not possible)
+  // if the disposition calls for a different window.
 
   // Only the current RenderFrameHost should be sending an OpenURL request.
   // Pending RenderFrameHost should know where it is navigating and pending
   // deletion RenderFrameHost shouldn't be trying to navigate.
   if (render_frame_host !=
       render_frame_host->frame_tree_node()->current_frame_host()) {
     return;
   }
 
   SiteInstance* current_site_instance = render_frame_host->GetSiteInstance();
@@ skipping 443 matching lines @@
   if (pending_entry != controller_->GetVisibleEntry() ||
       !should_preserve_entry) {
     controller_->DiscardPendingEntry(true);
 
     // Also force the UI to refresh.
     controller_->delegate()->NotifyNavigationStateChanged(INVALIDATE_TYPE_URL);
   }
 }
 
 }  // namespace content