Yeah, sorry forgot to mention XDK
What I meant to say was, Is there a particular checkbox on Construct 2 export that makes the plugin cordova inappbrowser install within XDK ?
Are you using the export to intel xdk option when you export your project in Construct 2 to Cordova? If the answer is yes again, dont worry because xdk will add the needed line to additions file when you emulate or build. If youre not checking this option, in xdk when you export your html5 Construct 2 exported files be sure youre selecting an option called like Use Cordova plugins(this will auto add the line too). Finally go to xdk develop tab with your project selected and be sure you have the needed line of code to include the plugin in the project.
Srry if you dont understand very well, my english is not so good yet