Returns true (1) if this context was used to load the extension identified
by |extension_id|. Other contexts sharing the same storage will also have
access to the extension (see HasExtension). This function must be called
on the browser process UI thread.
Returns true (1) if this context was used to load the extension identified by |extension_id|. Other contexts sharing the same storage will also have access to the extension (see HasExtension). This function must be called on the browser process UI thread.