Shadow DOM container for popup iframes (#623)

* Add support for injecting stylesheets into a custom parent node

* Add api.getStylesheetContent

* Add support for injecting a CSS file's content

* Add usePopupShadowDom option

* Use a per-parentNode cache

* Add support for using a shadow DOM wrapper around popup iframes

* Ignore the popup container instead of the frame

1 files changed, 4 insertions, 0 deletions

diff --git a/ext/mixed/js/api.js b/ext/mixed/js/api.js
index c54196e2..5c17d50e 100644
--- a/ext/mixed/js/api.js
+++ b/ext/mixed/js/api.js
@@ -121,6 +121,10 @@ const api = (() => {
             return this._invoke('injectStylesheet', {type, value});
         }
 
+        getStylesheetContent(url) {
+            return this._invoke('getStylesheetContent', {url});
+        }
+
         getEnvironmentInfo() {
             return this._invoke('getEnvironmentInfo');
         }