Bug 1896783 - don't rely on the ReportBrokenSite object existing as a window property, r=twisniewski,pbz,webcompat-reviewers

Unfortunately the addition in browser-siteProtections.js still makes this a
variable on the browser window, but refactoring the contents of that file to
be module-based is a separate effort.

Differential Revision: https://phabricator.services.mozilla.com/D210434

browser/base/content/browser-siteProtections.js

@@ -7,6 +7,7 @@
 ChromeUtils.defineESModuleGetters(this, {
   ContentBlockingAllowList:
     "resource://gre/modules/ContentBlockingAllowList.sys.mjs",
+  ReportBrokenSite: "resource:///modules/ReportBrokenSite.sys.mjs",
   SpecialMessageActions:
     "resource://messaging-system/lib/SpecialMessageActions.sys.mjs",
 });
@@ -1376,6 +1377,8 @@ var gProtectionsHandler = {
     if (!this._protectionsPopup) {
       let wrapper = document.getElementById("template-protections-popup");
       this._protectionsPopup = wrapper.content.firstElementChild;
+      this._protectionsPopup.addEventListener("popupshown", this);
+      this._protectionsPopup.addEventListener("popuphidden", this);
       wrapper.replaceWith(wrapper.content);
 
       this.maybeSetMilestoneCounterText();