Create a NavigationEntry for the initial blank page.

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 339d818953fafa5f75e9d3819d5bcdec2c2aae70..ad34b51e754d97b29942d3f82d617fde054efbfd 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -2722,6 +2722,17 @@ void RenderFrameImpl::didCommitProvisionalLoad(
   NavigationStateImpl* navigation_state =
       static_cast<NavigationStateImpl*>(document_state->navigation_state());
 
+  // We may see a "commit" for the initial blank page (e.g., when opening a
+  // popup with no URL).  This should not count as a navigation.  (Note that
+  // subsequent about:blank navigations marked as WebStandardCommit do count as
+  // new navigations and remain in history.)
+  if (render_view_->history_list_length_ == 0 &&
+      !frame->parent() &&
+      commit_type != blink::WebStandardCommit &&
+      navigation_state->request_params().nav_entry_id == 0 &&
+      GetLoadingUrl() == GURL(url::kAboutBlankURL))
+    return;
+
   if (proxy_routing_id_ != MSG_ROUTING_NONE) {
     RenderFrameProxy* proxy =
         RenderFrameProxy::FromRoutingID(proxy_routing_id_);
@@ -4612,8 +4623,6 @@ void RenderFrameImpl::NavigateInternal(
     }
     should_load_request = true;
   } else if (is_history_navigation) {
-    // We must know the page ID of the page we are navigating back to.
-    DCHECK_NE(request_params.page_id, -1);
     // We must know the nav entry ID of the page we are navigating back to,
     // which should be the case because history navigations are routed via the
     // browser.