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

content/browser/frame_host/navigation_handle_impl.cc

Index: content/browser/frame_host/navigation_handle_impl.cc
diff --git a/content/browser/frame_host/navigation_handle_impl.cc b/content/browser/frame_host/navigation_handle_impl.cc
index 93d6b99d2dfa2acf4898ce6216306ed2dd67302c..c12788fe172a4665a746632beb54353d331c1c2b 100644
--- a/content/browser/frame_host/navigation_handle_impl.cc
+++ b/content/browser/frame_host/navigation_handle_impl.cc
@@ -9,6 +9,7 @@
 #include "content/browser/browsing_data/clear_site_data_throttle.h"
 #include "content/browser/child_process_security_policy_impl.h"
 #include "content/browser/devtools/render_frame_devtools_agent_host.h"
+#include "content/browser/frame_host/ancestor_throttle.h"
 #include "content/browser/frame_host/debug_urls.h"
 #include "content/browser/frame_host/frame_tree_node.h"
 #include "content/browser/frame_host/navigator.h"
@@ -287,7 +288,9 @@ void NavigationHandleImpl::Resume() {
 
 void NavigationHandleImpl::CancelDeferredNavigation(
     NavigationThrottle::ThrottleCheckResult result) {
-  DCHECK(state_ == DEFERRING_START || state_ == DEFERRING_REDIRECT);
+  DCHECK(state_ == DEFERRING_START ||
+         state_ == DEFERRING_REDIRECT ||
+         state_ == DEFERRING_RESPONSE);
   DCHECK(result == NavigationThrottle::CANCEL_AND_IGNORE ||
          result == NavigationThrottle::CANCEL);
   state_ = CANCELING;
@@ -592,6 +595,9 @@ NavigationHandleImpl::CheckWillStartRequest() {
         state_ = DEFERRING_START;
         next_index_ = i + 1;
         return result;
+
+      case NavigationThrottle::BLOCK_RESPONSE:
+        NOTREACHED();
     }
   }
   next_index_ = 0;
@@ -622,6 +628,7 @@ NavigationHandleImpl::CheckWillRedirectRequest() {
         return result;
 
       case NavigationThrottle::BLOCK_REQUEST:
+      case NavigationThrottle::BLOCK_RESPONSE:
         NOTREACHED();
     }
   }
@@ -649,6 +656,7 @@ NavigationHandleImpl::CheckWillProcessResponse() {
 
       case NavigationThrottle::CANCEL:
       case NavigationThrottle::CANCEL_AND_IGNORE:
+      case NavigationThrottle::BLOCK_RESPONSE:
         state_ = CANCELING;
         return result;
 
@@ -787,6 +795,11 @@ void NavigationHandleImpl::RegisterNavigationThrottles() {
   if (clear_site_data_throttle)
     throttles_to_register.push_back(std::move(clear_site_data_throttle));
 
+  std::unique_ptr<content::NavigationThrottle> ancestor_throttle =
+      content::AncestorThrottle::MaybeCreateThrottleFor(this);
+  if (ancestor_throttle)
+    throttles_.push_back(std::move(ancestor_throttle));
+
   if (throttles_to_register.size() > 0) {
     throttles_.insert(throttles_.begin(), throttles_to_register.begin(),
                       throttles_to_register.end());