Bug 1715142 - clear the TLS session cache in SetDisableAllSecurityChecksAndLetAttackersInterceptMyData r=rmf

Previously, SetDisableAllSecurityChecksAndLetAttackersInterceptMyData would
only work as expected if another operation happened to clear the TLS session
cache (namely, changing a preference that caused nsNSSComponent to change its
TLS options and clear the TLS session cache). This patch ensures that this
function works without relying on such coincidences.

Differential Revision: https://phabricator.services.mozilla.com/D117495

security/manager/ssl/nsCertOverrideService.cpp

@@ -827,8 +827,18 @@ nsCertOverrideService::
     return NS_ERROR_NOT_AVAILABLE;
   }
 
-  MutexAutoLock lock(mMutex);
-  mDisableAllSecurityCheck = aDisable;
+  {
+    MutexAutoLock lock(mMutex);
+    mDisableAllSecurityCheck = aDisable;
+  }
+
+  nsCOMPtr<nsINSSComponent> nss(do_GetService(PSM_COMPONENT_CONTRACTID));
+  if (nss) {
+    nss->ClearSSLExternalAndInternalSessionCache();
+  } else {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
   return NS_OK;
 }