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 0b0edb3b70d35d45640beaec68056bcb001ba97e..9050689f79962a60fc195e9d821c71b66bd1e32a 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -327,6 +327,8 @@ 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;
@@ -626,6 +628,10 @@ 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;