Chrome, for some reason, doesn't allow the injection of the speed hack anymore. It's been that way for quite a while now. I think it has something to do with .dll injection, but can't remember off the top of my head. There are plugins for CE that force inject, which makes things like speedhack and certain otherwise blocked stealthedit functions work. I'm not the best at this stuff yet; still learning. My attempt to use the force injection plugin I found was not so successful, it caused some crashing/freezing. One method, with games like this which have export saves (long streams of characters that you can export and then import to regain save data) is to take your save export from Chrome, open an internet explorer window and import the game there, and CE will have no problem speedhacking there. Then, if you prefer to play in Chrome, you can export the gains from IE and import back to your game in Chrome.
Another helpful tip is that actual string of characters that is your save game for export/import. They are usually pretty simple base64 data that contains the information about your save. You can use an online base64 converter to translate the string to various formats; text, decimal, hex, etc. Usually, one of them will make sense. You can then edit the values there, convert back to base64, then use it as an import. Note: always keep a back-up in a notepad of your original string, just in case you mess up the edit. Wouldn't want to import an errored string and have to start all over from zero over a silly mistake!
I've got idle fight running idle (ha ha) right now while I'm off working. I'll put some work into trying to find the values methods later when I'm not busy. It doesn't seem to be secure in anyway, like Idle Ants, for instance, where the values are server-side and linked in. The most common methods of hiding values are (value*8) and (value *8+6). I'll check into it later. Til then, happy fighting!