(Re-)introduce AncestorThrottle to handle 'X-Frame-Options'.

content/browser/site_per_process_browsertest.cc

Index: content/browser/site_per_process_browsertest.cc
diff --git a/content/browser/site_per_process_browsertest.cc b/content/browser/site_per_process_browsertest.cc
index 71b1dcbbd9740ba1a18474acc817beba9c2d4e32..4394f7378aa15597156d6f12b7d0746ae6b36015 100644
--- a/content/browser/site_per_process_browsertest.cc
+++ b/content/browser/site_per_process_browsertest.cc
@@ -6947,7 +6947,7 @@ IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest,
 
     // Ensure that we don't use the blocked URL as the blocked frame's last
     // committed URL (see https://crbug.com/622385).
-    EXPECT_NE(root->child_at(0)->current_frame_host()->GetLastCommittedURL(),
+    EXPECT_NE(root->child_at(0)->current_frame_host()->last_successful_url(),

[alexmos, 2016/12/20 01:34:39]

Is this change still necessary?  Committing a blank page should make this work
with the old check again.  (The full discussion about it was at 
https://codereview.chromium.org/2321503002)

[arthursonzogni, 2016/12/20 10:29:43]

You are right.

               blocked_urls[i]);
 
     // The blocked frame should still fire a load event in its parent's process.