| Index: Source/devtools/front_end/extensions/ExtensionAPI.js | 
| diff --git a/Source/devtools/front_end/extensions/ExtensionAPI.js b/Source/devtools/front_end/extensions/ExtensionAPI.js | 
| index 5bbfbb19e476c1cb7fa3c706eea7cf4128c6c5c1..76bf23876678df40d95c6769ccfeea4028e30335 100644 | 
| --- a/Source/devtools/front_end/extensions/ExtensionAPI.js | 
| +++ b/Source/devtools/front_end/extensions/ExtensionAPI.js | 
| @@ -889,7 +889,7 @@ ExtensionServerClient.prototype = { | 
| */ | 
| nextObjectId: function() | 
| { | 
| -        return injectedScriptId + "_" + ++this._lastObjectId; | 
| +        return injectedScriptId.toString() + "_" + ++this._lastObjectId; | 
| }, | 
|  | 
| _registerCallback: function(callback) | 
|  |