Ensure that before creating proxy of site A, RVH of site A is initialized.

content/browser/frame_host/frame_tree.cc

Index: content/browser/frame_host/frame_tree.cc
diff --git a/content/browser/frame_host/frame_tree.cc b/content/browser/frame_host/frame_tree.cc
index 96890f09075d9e438e750271b3405f8ae3b2d80f..79ca6b73c1a368c6ae49efd5a98c8c728872554a 100644
--- a/content/browser/frame_host/frame_tree.cc
+++ b/content/browser/frame_host/frame_tree.cc
@@ -204,7 +204,7 @@ void FrameTree::CreateProxiesForSiteInstance(
   if (!source->IsMainFrame()) {
     RenderViewHostImpl* render_view_host =
         source->frame_tree()->GetRenderViewHost(site_instance);
-    if (!render_view_host) {
+    if (!render_view_host || !render_view_host->IsRenderViewLive()) {
       root()->render_manager()->CreateRenderFrame(
           site_instance, nullptr, MSG_ROUTING_NONE,
           CREATE_RF_SWAPPED_OUT | CREATE_RF_HIDDEN, nullptr);
@@ -265,8 +265,10 @@ RenderViewHostImpl* FrameTree::CreateRenderViewHost(SiteInstance* site_instance,
     // Otherwise return the existing RenderViewHost for the SiteInstance.
     RenderFrameHostImpl* main_frame = static_cast<RenderFrameHostImpl*>(
         iter->second->GetMainFrame());
-    if (main_frame->frame_tree_node()->render_manager()->IsPendingDeletion(
-            main_frame)) {
+    // |main_frame| is NULL when the RVH is uninitialized.
+    if (main_frame &&
+            main_frame->frame_tree_node()->render_manager()->IsPendingDeletion(
+                main_frame)) {
       render_view_host_pending_shutdown_map_.insert(
           std::pair<int, RenderViewHostImpl*>(site_instance->GetId(),
                                               iter->second));