Navigation transitions: Block first response until after transitions have run.

content/browser/loader/resource_dispatcher_host_impl.h

Index: content/browser/loader/resource_dispatcher_host_impl.h
diff --git a/content/browser/loader/resource_dispatcher_host_impl.h b/content/browser/loader/resource_dispatcher_host_impl.h
index 185fb0b075028941d540d9aa93df6314f71b1fa4..6cf24727e9f6ae46dce5fa6a1a0c10202b8f2be9 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.h
+++ b/content/browser/loader/resource_dispatcher_host_impl.h
@@ -103,6 +103,9 @@ class CONTENT_EXPORT ResourceDispatcherHostImpl
   // Notify the ResourceDispatcherHostImpl of a resource context destruction.
   void RemoveResourceContext(ResourceContext* context);
 
+  // Resumes a request that deferred at response start.
+  void ResumeResponseDeferredAtStart(const GlobalRequestID& id);
+
   // Force cancels any pending requests for the given |context|. This is
   // necessary to ensure that before |context| goes away, all requests
   // for it are dead.