PlzNavigate: Enforce 'form-action' CSP on the browser-side.

content/browser/frame_host/interstitial_page_navigator_impl.cc

Index: content/browser/frame_host/interstitial_page_navigator_impl.cc
diff --git a/content/browser/frame_host/interstitial_page_navigator_impl.cc b/content/browser/frame_host/interstitial_page_navigator_impl.cc
index 4e41462dfaa4b8bc0951ecad2b075d57c3d8754b..76f38408d42a203f0efb6ec1c6a346beee82b7eb 100644
--- a/content/browser/frame_host/interstitial_page_navigator_impl.cc
+++ b/content/browser/frame_host/interstitial_page_navigator_impl.cc
@@ -36,12 +36,13 @@ void InterstitialPageNavigatorImpl::DidStartProvisionalLoad(
   DCHECK(!render_frame_host->navigation_handle());
   render_frame_host->SetNavigationHandle(NavigationHandleImpl::Create(
       url, redirect_chain, render_frame_host->frame_tree_node(),
-      false,                /* is_renderer_initiated */
-      false,                /* is_synchronous */
-      navigation_start,     /* navigation_state */
-      0,                    /* pending_nav_entry_id */
-      false,                /* started_in_context_menu */
-      CSPDisposition::CHECK /* should_check_main_world_csp */
+      false,                 /* is_renderer_initiated */
+      false,                 /* is_synchronous */
+      navigation_start,      /* navigation_state */
+      0,                     /* pending_nav_entry_id */
+      false,                 /* started_in_context_menu */
+      CSPDisposition::CHECK, /* should_check_main_world_csp */
+      false                  /* is_form_submission */
       ));
 }