Replacement for bookmarklets with better referrer handling.
Usage
Upload post via context menu:
Find a picture on the web
Right click on the image
Click Upload to Danbooru
Upload post via page action:
Navigate to one of the supported sites
Navigate to the image view page
Click on the Danbooru ("cardboard box") icon in the address bar (multiple images automatically detected)
Note: Although this extension allows you to upload images from any website, you should be careful to not to upload thumbnail/sample from sites not supported by Danbooru. List of the supported sites can be found here.
