Keep a copy of page id in RenderViewHost.

content/browser/renderer_host/render_view_host_impl.cc

Index: content/browser/renderer_host/render_view_host_impl.cc
diff --git a/content/browser/renderer_host/render_view_host_impl.cc b/content/browser/renderer_host/render_view_host_impl.cc
index b49b3396fda66eaacb54672da74a93cf9c0f3469..b03d28fa685cafacbc1f1d2addf55f140067a5e5 100644
--- a/content/browser/renderer_host/render_view_host_impl.cc
+++ b/content/browser/renderer_host/render_view_host_impl.cc
@@ -190,6 +190,7 @@ RenderViewHostImpl::RenderViewHostImpl(
       waiting_for_drag_context_response_(false),
       enabled_bindings_(0),
       navigations_suspended_(false),
+      page_id_(-1),
       main_frame_routing_id_(main_frame_routing_id),
       run_modal_reply_msg_(NULL),
       run_modal_opener_id_(MSG_ROUTING_NONE),
@@ -283,8 +284,10 @@ bool RenderViewHostImpl::CreateRenderView(
   // Ensure the RenderView starts with a next_page_id larger than any existing
   // page ID it might be asked to render.
   int32 next_page_id = 1;
-  if (max_page_id > -1)
+  if (max_page_id > -1) {
     next_page_id = max_page_id + 1;
+    page_id_ = max_page_id;
+  }
 
   ViewMsg_New_Params params;
   params.renderer_preferences =
@@ -1111,6 +1114,7 @@ void RenderViewHostImpl::OnRenderProcessGone(int status, int exit_code) {
 }
 
 void RenderViewHostImpl::OnUpdateState(int32 page_id, const PageState& state) {
+  CHECK_EQ(page_id_, page_id);
   // Without this check, the renderer can trick the browser into using
   // filenames it can't access in a future session restore.
   if (!CanAccessFilesOfPageState(state)) {
@@ -1118,12 +1122,13 @@ void RenderViewHostImpl::OnUpdateState(int32 page_id, const PageState& state) {
     return;
   }
 
-  delegate_->UpdateState(this, page_id, state);
+  delegate_->UpdateState(this, page_id_, state);
 }
 
 void RenderViewHostImpl::OnUpdateTargetURL(int32 page_id, const GURL& url) {
+  CHECK_EQ(page_id_, page_id);
   if (IsRVHStateActive(rvh_state_))
-    delegate_->UpdateTargetURL(page_id, url);
+    delegate_->UpdateTargetURL(page_id_, url);
 
   // Send a notification back to the renderer that we are ready to
   // receive more target urls.