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

content/browser/loader/cross_site_resource_handler.h

Index: content/browser/loader/cross_site_resource_handler.h
diff --git a/content/browser/loader/cross_site_resource_handler.h b/content/browser/loader/cross_site_resource_handler.h
index df6c7a39bbf4aacbd00a548c68811ade0ee10d07..8e683b4dfe3964a913476ade85a9818888354de0 100644
--- a/content/browser/loader/cross_site_resource_handler.h
+++ b/content/browser/loader/cross_site_resource_handler.h
@@ -53,6 +53,14 @@ class CrossSiteResourceHandler : public LayeredResourceHandler {
   CONTENT_EXPORT static void SetLeakRequestsForTesting(
       bool leak_requests_for_testing);
 
+  // Navigations are deferred at OnResponseStarted to parse out any navigation
+  // transition link headers, and give the navigation transition (if it exists)
+  // a chance to run.
+  void ResumeResponseDeferredAtStart(int request_id);
+
+  // Returns whether the handler is deferred.
+  bool is_deferred_for_testing() const { return did_defer_; }
+
  private:
   // Prepare to render the cross-site response in a new RenderViewHost, by
   // telling the old RenderViewHost to run its onunload handler.
@@ -66,6 +74,14 @@ class CrossSiteResourceHandler : public LayeredResourceHandler {
                                      ResourceResponse* response,
                                      bool* defer);
 
+  bool OnNavigationTransitionResponseStarted(int request_id,
+                                             ResourceResponse* response,
+                                             bool* defer);
+
+  bool OnNormalResponseStarted(int request_id,
+                               ResourceResponse* response,
+                               bool* defer);
+
   void ResumeOrTransfer(bool is_transfer);
   void ResumeIfDeferred();