Implement NavigationThrottle::BLOCK_REQUEST_AND_COLLAPSE.

content/browser/frame_host/render_frame_host_manager.h

Index: content/browser/frame_host/render_frame_host_manager.h
diff --git a/content/browser/frame_host/render_frame_host_manager.h b/content/browser/frame_host/render_frame_host_manager.h
index 9a7d3ad05e2731212b9050df87f51c47d4ab81b8..9d92c7a43fa33d43cb60bb21852f6578a0c705fd 100644
--- a/content/browser/frame_host/render_frame_host_manager.h
+++ b/content/browser/frame_host/render_frame_host_manager.h
@@ -435,6 +435,12 @@ class CONTENT_EXPORT RenderFrameHostManager
   // when the frame changes its setting.
   void OnEnforceInsecureRequestPolicy(blink::WebInsecureRequestPolicy policy);
 
+  // Called on a child frame to propagate, to the child frame's owner element in
+  // the parent frame, a change in whether that frame owner element should be
+  // collapsed. Note that information here flows in the exactly opposite
+  // direction than it does for OnDidUpdateFrameOwnerProperties.
+  void OnDidUpdateFrameOwnerCollapsedState(bool collapsed);
+
   // Called on a frame to notify it that its out-of-process parent frame
   // changed a property (such as allowFullscreen) on its <iframe> element.
   // Sends updated FrameOwnerProperties to the RenderFrame and to all proxies,