Registers a custom URL scheme that can be used in match patterns.
This method should be used to register any custom URL schemes used by the app for the extension base URLs,
other than webkit-extension, or if extensions should have access to other supported URL schemes when using <all_urls>.
Registers a custom URL scheme that can be used in match patterns.
This method should be used to register any custom URL schemes used by the app for the extension base URLs, other than webkit-extension, or if extensions should have access to other supported URL schemes when using <all_urls>.