Ensure the NavigationHandle's nav entry ID is updated during transfers.

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 107 matching lines @@
     const base::TimeTicks& navigation_start) {
   bool is_main_frame = render_frame_host->frame_tree_node()->IsMainFrame();
   bool is_error_page = (url.spec() == kUnreachableWebDataURL);
   bool is_iframe_srcdoc = (url.spec() == kAboutSrcDocURL);
   GURL validated_url(url);
   RenderProcessHost* render_process_host = render_frame_host->GetProcess();
   render_process_host->FilterURL(false, &validated_url);
 
   if (is_main_frame && !is_error_page) {
     DidStartMainFrameNavigation(validated_url,
-                                render_frame_host->GetSiteInstance());
+                                render_frame_host->GetSiteInstance(),
+                                render_frame_host->navigation_handle());
   }
 
   if (delegate_) {
     // Notify the observer about the start of the provisional load.
     delegate_->DidStartProvisionalLoad(render_frame_host, validated_url,
                                        is_error_page, is_iframe_srcdoc);
   }
 
   if (is_error_page || IsBrowserSideNavigationEnabled())
     return;
@@ skipping 700 matching lines @@
   if (frame_tree_node->IsMainFrame()) {
     // Renderer-initiated main-frame navigations that need to swap processes
     // will go to the browser via a OpenURL call, and then be handled by the
     // same code path as browser-initiated navigations. For renderer-initiated
     // main frame navigation that start via a BeginNavigation IPC, the
     // RenderFrameHost will not be swapped. Therefore it is safe to call
     // DidStartMainFrameNavigation with the SiteInstance from the current
     // RenderFrameHost.
     DidStartMainFrameNavigation(
         common_params.url,
-        frame_tree_node->current_frame_host()->GetSiteInstance());
+        frame_tree_node->current_frame_host()->GetSiteInstance(), nullptr);
     navigation_data_.reset();
   }
 
   // For main frames, NavigationHandle will be created after the call to
   // |DidStartMainFrameNavigation|, so it receives the most up to date pending
   // entry from the NavigationController.
   NavigationEntry* pending_entry = controller_->GetPendingEntry();
   navigation_request->CreateNavigationHandle(
       pending_entry ? pending_entry->GetUniqueID() : 0);
   navigation_request->BeginNavigation();
@@ skipping 223 matching lines @@
         time_to_commit);
     UMA_HISTOGRAM_TIMES(
         "Navigation.TimeToURLJobStart_ExistingRenderer_BeforeUnloadDiscounted",
         time_to_network);
   }
   navigation_data_.reset();
 }
 
 void NavigatorImpl::DidStartMainFrameNavigation(
     const GURL& url,
-    SiteInstanceImpl* site_instance) {
+    SiteInstanceImpl* site_instance,
+    NavigationHandleImpl* navigation_handle) {
   // If there is no browser-initiated pending entry for this navigation and it
   // is not for the error URL, create a pending entry using the current
   // SiteInstance, and ensure the address bar updates accordingly.  We don't
   // know the referrer or extra headers at this point, but the referrer will
   // be set properly upon commit.
   NavigationEntryImpl* pending_entry = controller_->GetPendingEntry();
   bool has_browser_initiated_pending_entry =
       pending_entry && !pending_entry->is_renderer_initiated();
   if (!has_browser_initiated_pending_entry) {
     scoped_ptr<NavigationEntryImpl> entry =
         NavigationEntryImpl::FromNavigationEntry(
             controller_->CreateNavigationEntry(
                 url, content::Referrer(), ui::PAGE_TRANSITION_LINK,
                 true /* is_renderer_initiated */, std::string(),
                 controller_->GetBrowserContext()));
     entry->set_site_instance(site_instance);
     // TODO(creis): If there's a pending entry already, find a safe way to
     // update it instead of replacing it and copying over things like this.
+    // That will allow us to skip the NavigationHandle update below as well.
     if (pending_entry) {
       entry->set_transferred_global_request_id(
           pending_entry->transferred_global_request_id());
       entry->set_should_replace_entry(pending_entry->should_replace_entry());
       entry->SetRedirectChain(pending_entry->GetRedirectChain());
     }
+
+    // If there's a current NavigationHandle, update its pending NavEntry ID.

[Charlie Harrison, 2016/03/11 15:15:14]

Good catch.

+    // This is necessary for transfer navigations.  The handle may be null in
+    // PlzNavigate.
+    if (navigation_handle)
+      navigation_handle->set_pending_nav_entry_id(entry->GetUniqueID());
+
     controller_->SetPendingEntry(std::move(entry));
     if (delegate_)
       delegate_->NotifyChangedNavigationState(content::INVALIDATE_TYPE_URL);
   }
 }
 
 }  // namespace content