Fix IsRenderFrameLive and use it in RenderFrameHostManager.

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 8cf5a0f673200bf3091efd98c5148bbd41fb4a4e..9d60c2d1a749734a18f588d7952f66ed6e6cb397 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -1882,13 +1882,16 @@ bool WebContentsImpl::NavigateToPendingEntry(
     NavigationController::ReloadType reload_type) {
   FrameTreeNode* node = frame_tree_.root();
 
-  // If we are using --site-per-process, we should navigate in the FrameTreeNode
-  // specified in the pending entry.
+  // Navigate in the FrameTreeNode specified in the pending entry, if any.  This
+  // is currently only used in --site-per-process and tests.
   NavigationEntryImpl* pending_entry =
       NavigationEntryImpl::FromNavigationEntry(controller_.GetPendingEntry());
-  if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kSitePerProcess) &&
-      pending_entry->frame_tree_node_id() != -1) {
-    node = frame_tree_.FindByID(pending_entry->frame_tree_node_id());
+  if (pending_entry->frame_tree_node_id() != -1) {
+    FrameTreeNode* subframe =
+        frame_tree_.FindByID(pending_entry->frame_tree_node_id());
+    DCHECK(subframe);
+    if (subframe)
+      node = subframe;
   }
 
   return node->navigator()->NavigateToPendingEntry(