Have the unload event execute in background on cross-site navigations

content/public/test/mock_render_process_host.cc

Index: content/public/test/mock_render_process_host.cc
diff --git a/content/public/test/mock_render_process_host.cc b/content/public/test/mock_render_process_host.cc
index 9ef67e3cfd438cdc774047e70fbeba6756f92548..7206bf1b8c7f025a4c66c1d1d6d2e5856b350c39 100644
--- a/content/public/test/mock_render_process_host.cc
+++ b/content/public/test/mock_render_process_host.cc
@@ -12,6 +12,7 @@
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/common/child_process_host_impl.h"
+#include "content/public/browser/global_request_id.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/render_widget_host_iterator.h"
@@ -255,6 +256,9 @@ void MockRenderProcessHost::SurfaceUpdated(int32 surface_id) {
 void MockRenderProcessHost::ResumeRequestsForView(int route_id) {
 }
 
+void MockRenderProcessHost::ResumeDeferredNavigation(
+      const GlobalRequestID& request_id) {
+}
 
 bool MockRenderProcessHost::OnMessageReceived(const IPC::Message& msg) {
   IPC::Listener* listener = listeners_.Lookup(msg.routing_id());