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

content/browser/frame_host/navigation_request.cc

Index: content/browser/frame_host/navigation_request.cc
diff --git a/content/browser/frame_host/navigation_request.cc b/content/browser/frame_host/navigation_request.cc
index c85d165de13f6cb11c0e3d7e553d6019a34eadcb..240192e373df41c42a791b9a42be1fef9fd4fc40 100644
--- a/content/browser/frame_host/navigation_request.cc
+++ b/content/browser/frame_host/navigation_request.cc
@@ -217,6 +217,7 @@ std::unique_ptr<NavigationRequest> NavigationRequest::CreateBrowserInitiated(
                             false,  // skip_service_worker
                             REQUEST_CONTEXT_TYPE_LOCATION,
                             blink::WebMixedContentContextType::Blockable,
+                            false,  // is_form_submission
                             initiator),
       entry.ConstructRequestNavigationParams(
           frame_entry, common_params.url, common_params.method,
@@ -394,7 +395,8 @@ void NavigationRequest::CreateNavigationHandle(int pending_nav_entry_id) {
                                    common_params_.navigation_type),
           common_params_.navigation_start, pending_nav_entry_id,
           false,  // started_in_context_menu
-          common_params_.should_bypass_main_world_csp);
+          common_params_.should_bypass_main_world_csp,
+          begin_params_.is_form_submission);
 
   if (!frame_tree_node->navigation_request()) {
     // A callback could have cancelled this request synchronously in which case