Replicate feature policy container policies.

third_party/WebKit/Source/core/html/HTMLFrameElementBase.h

Index: third_party/WebKit/Source/core/html/HTMLFrameElementBase.h
diff --git a/third_party/WebKit/Source/core/html/HTMLFrameElementBase.h b/third_party/WebKit/Source/core/html/HTMLFrameElementBase.h
index 6f95790f41c330d3b3eb10f1165b0fec786242c5..fc6789f29b1866c65bc1181035680474b4f04854 100644
--- a/third_party/WebKit/Source/core/html/HTMLFrameElementBase.h
+++ b/third_party/WebKit/Source/core/html/HTMLFrameElementBase.h
@@ -38,10 +38,18 @@ class CORE_EXPORT HTMLFrameElementBase : public HTMLFrameOwnerElement {
   int MarginWidth() const final { return margin_width_; }
   int MarginHeight() const final { return margin_height_; }
 
+  // Return the origin which is to be used for feature policy container
+  // policies, when a specific origin is needed. This supports the "allow"
+  // attribute, which uses the "src" attribute to determine the origin when the
+  // frame is constructed. It also takes into account the frame's sandbox
+  // status, and whether the frame should inherit its parent's origin.
+  const RefPtr<SecurityOrigin> GetOriginForFeaturePolicy() const override;
+
  protected:
   HTMLFrameElementBase(const QualifiedName&, Document&);
 
   void ParseAttribute(const AttributeModificationParams&) override;
+
   InsertionNotificationRequest InsertedInto(ContainerNode*) override;
   void DidNotifySubtreeInsertionsToDocument() final;
   void AttachLayoutTree(const AttachContext& = AttachContext()) override;