| Index: lib/cssInjection.js | 
| =================================================================== | 
| --- a/lib/cssInjection.js | 
| +++ b/lib/cssInjection.js | 
| @@ -161,7 +161,7 @@ | 
| { | 
| let selectors = []; | 
| let emulatedPatterns = []; | 
| - let trace = devtools && devtools.hasPanel(sender.page); | 
| + let trace = devtools.hasPanel(sender.page.id); | 
| let inline = !userStyleSheetsSupported; | 
| if (!checkWhitelisted(sender.page, sender.frame, |