Don't show current RenderWidgetHostView while interstitial is showing.

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/logging.h"
 #include "base/metrics/histogram_macros.h"
@@ skipping 245 matching lines @@
     // interstitial's "failed" message (as a result of the cancel) when we're on
     // the second one. We can't tell this apart, so we think we're tearing down
     // the current page which will cause a crash later on.
     //
     // http://code.google.com/p/chromium/issues/detail?id=2855
     // Because this will not tear down the interstitial properly, if "back" is
     // back to another tab type, the interstitial will still be somewhat alive
     // in the previous tab type. If you navigate somewhere that activates the
     // tab with the interstitial again, you'll see a flash before the new load
     // commits of the interstitial page.
-    FrameTreeNode* root =
-        render_frame_host->frame_tree_node()->frame_tree()->root();
-    if (root->render_manager()->interstitial_page() != NULL) {
+    if (delegate_ && delegate_->ShowingInterstitialPage()) {
       LOG(WARNING) << "Discarding message during interstitial.";
       return;
     }
 
     // We used to cancel the pending renderer here for cross-site downloads.
     // However, it's not safe to do that because the download logic repeatedly
     // looks for this WebContents based on a render ID. Instead, we just
     // leave the pending renderer around until the next navigation event
     // (Navigate, DidNavigate, etc), which will clean it up properly.
     //
@@ skipping 1019 matching lines @@
     if (navigation_handle)
       navigation_handle->update_entry_id_for_transfer(entry->GetUniqueID());
 
     controller_->SetPendingEntry(std::move(entry));
     if (delegate_)
       delegate_->NotifyChangedNavigationState(content::INVALIDATE_TYPE_URL);
   }
 }
 
 }  // namespace content