Bug 1627859 - Fix case where we don't read IPC policies in time. r=ckerschb

Differential Revision: https://phabricator.services.mozilla.com/D69905

--HG--
extra : moz-landing-system : lando

dom/security/nsCSPContext.cpp

@@ -194,6 +194,7 @@ bool nsCSPContext::permitsInternal(
     const nsAString& aNonce, bool aIsPreload, bool aSpecific,
     bool aSendViolationReports, bool aSendContentLocationInViolationReports,
     bool aParserCreated) {
+  EnsureIPCPoliciesRead();
   bool permits = true;
 
   nsAutoString violatedDirective;