Add is_srcdoc to FrameNavigationEntry and restore about::srcdoc URL.

content/browser/frame_host/navigator_impl.cc

Index: content/browser/frame_host/navigator_impl.cc
diff --git a/content/browser/frame_host/navigator_impl.cc b/content/browser/frame_host/navigator_impl.cc
index ea6c3478483e831ff9c1a2247f1cbcef8a5d7e43..c7879975f6d58cfd51637683b8ad4153f4da6515 100644
--- a/content/browser/frame_host/navigator_impl.cc
+++ b/content/browser/frame_host/navigator_impl.cc
@@ -892,7 +892,7 @@ void NavigatorImpl::RequestTransferURL(
         node, -1, -1, nullptr,
         static_cast<SiteInstanceImpl*>(source_site_instance),
         dest_url, referrer_to_use, redirect_chain, PageState(), method,
-        -1);
+        -1, false);
   } else {
     // Main frame case.
     entry = NavigationEntryImpl::FromNavigationEntry(
@@ -925,7 +925,7 @@ void NavigatorImpl::RequestTransferURL(
     frame_entry = new FrameNavigationEntry(
         node->unique_name(), -1, -1, nullptr,
         static_cast<SiteInstanceImpl*>(source_site_instance), dest_url,
-        referrer_to_use, method, -1);
+        referrer_to_use, method, -1, false);
   }
   NavigateToEntry(node, *frame_entry, *entry.get(), ReloadType::NONE, false,
                   false, false, post_body);