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

content/browser/web_contents/web_contents_impl.h

Index: content/browser/web_contents/web_contents_impl.h
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index 8278efbefb179207529d871450e75c25602ab472..5f3866def8de9a0186929cb81eeaedcace6d14a8 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -328,6 +328,8 @@ class CONTENT_EXPORT WebContentsImpl
   virtual void DidStartLoading(RenderFrameHost* render_frame_host,
                                bool to_different_document) OVERRIDE;
   virtual void SwappedOut(RenderFrameHost* render_frame_host) OVERRIDE;
+  virtual void DidDeferAfterResponseStarted() OVERRIDE;
+  virtual bool WillHandleDeferAfterResponseStarted() OVERRIDE;
   virtual void WorkerCrashed(RenderFrameHost* render_frame_host) OVERRIDE;
   virtual void ShowContextMenu(RenderFrameHost* render_frame_host,
                                const ContextMenuParams& params) OVERRIDE;
@@ -625,6 +627,10 @@ class CONTENT_EXPORT WebContentsImpl
   // currently focused frame.
   void SelectRange(const gfx::Point& start, const gfx::Point& end);
 
+  // Notifies the main frame that it can continue navigation (if it was deferred
+  // immediately at first response).
+  void ResumeResponseDeferredAtStart();
+
  private:
   friend class TestNavigationObserver;
   friend class WebContentsAddedObserver;