Remove the extra copy of page id.

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 b0ddbdec789ba2c818087d9420daf51af597e76f..933e93de4d35861da7b9fc420b885ad21d16464e 100644
--- a/content/browser/renderer_host/render_view_host_impl.cc
+++ b/content/browser/renderer_host/render_view_host_impl.cc
@@ -213,7 +213,6 @@ RenderViewHostImpl::RenderViewHostImpl(
       instance_(static_cast<SiteInstanceImpl*>(instance)),
       waiting_for_drag_context_response_(false),
       enabled_bindings_(0),
-      page_id_(-1),
       is_active_(!swapped_out),
       is_swapped_out_(swapped_out),
       main_frame_routing_id_(main_frame_routing_id),
@@ -1027,12 +1026,6 @@ void RenderViewHostImpl::OnRenderProcessGone(int status, int exit_code) {
 }
 
 void RenderViewHostImpl::OnUpdateState(int32 page_id, const PageState& state) {
-  // If the following DCHECK fails, you have encountered a tricky edge-case that
-  // has evaded reproduction for a very long time. Please report what you were
-  // doing on http://crbug.com/407376, whether or not you can reproduce the
-  // failure.
-  DCHECK_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)) {