Propagating csp attribute changes on frameOwnerPropertiesChanged()

content/common/frame_owner_properties.h

Index: content/common/frame_owner_properties.h
diff --git a/content/common/frame_owner_properties.h b/content/common/frame_owner_properties.h
index 12325a9483fc9f0e8b5f02bbdb34c848778baeb4..157c82334ddc3f30d1fd3145106a96abe19e930e 100644
--- a/content/common/frame_owner_properties.h
+++ b/content/common/frame_owner_properties.h
@@ -34,6 +34,14 @@ struct CONTENT_EXPORT FrameOwnerProperties {
   int margin_width;
   int margin_height;
   bool allow_fullscreen;
+
+  // An experimental attribute to be used by a parent frame to enforce CSP on a
+  // subframe. This is different from replicated CSP headers kept in
+  // FrameReplicationState that keep track of CSP headers currently in effect
+  // for a frame. See https://crbug.com/647588 and
+  // https://www.w3.org/TR/csp-embedded-enforcement/#required-csp
+  std::string required_csp;
+
   std::vector<blink::WebPermissionType> delegated_permissions;
 };