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

third_party/WebKit/Source/core/loader/DocumentLoader.h

Index: third_party/WebKit/Source/core/loader/DocumentLoader.h
diff --git a/third_party/WebKit/Source/core/loader/DocumentLoader.h b/third_party/WebKit/Source/core/loader/DocumentLoader.h
index 21af660142a3493b92cd39e5a1f50910b72cedba..1c70f889c55805b3e3001484fc27c495dec2f048 100644
--- a/third_party/WebKit/Source/core/loader/DocumentLoader.h
+++ b/third_party/WebKit/Source/core/loader/DocumentLoader.h
@@ -170,12 +170,8 @@ class CORE_EXPORT DocumentLoader
   };
   InitialScrollState& initialScrollState() { return m_initialScrollState; }
 
-  void setWasBlockedAfterXFrameOptionsOrCSP() {
-    m_wasBlockedAfterXFrameOptionsOrCSP = true;
-  }
-  bool wasBlockedAfterXFrameOptionsOrCSP() {
-    return m_wasBlockedAfterXFrameOptionsOrCSP;
-  }
+  void setWasBlockedAfterCSP() { m_wasBlockedAfterCSP = true; }
+  bool wasBlockedAfterCSP() { return m_wasBlockedAfterCSP; }
 
   void dispatchLinkHeaderPreloads(ViewportDescriptionWrapper*,
                                   LinkLoader::MediaPreloadPolicy);
@@ -215,7 +211,7 @@ class CORE_EXPORT DocumentLoader
   bool maybeCreateArchive();
 
   void finishedLoading(double finishTime);
-  void cancelLoadAfterXFrameOptionsOrCSPDenied(const ResourceResponse&);
+  void cancelLoadAfterCSPDenied(const ResourceResponse&);
   bool redirectReceived(Resource*,
                         const ResourceRequest&,
                         const ResourceResponse&) final;
@@ -271,7 +267,7 @@ class CORE_EXPORT DocumentLoader
   ClientHintsPreferences m_clientHintsPreferences;
   InitialScrollState m_initialScrollState;
 
-  bool m_wasBlockedAfterXFrameOptionsOrCSP;
+  bool m_wasBlockedAfterCSP;
 
   enum State {
     NotStarted,