Created attachment 131353 [details] [review]
Same as bug 99366, but instead of "chromium", "google-chrome-unstable" and "google-chrome-beta" should be added.
On my updated Gentoo GNU/Linux system, xdg-open doesn't find google-chrome-unstable nor google-chrome-beta when trying to open a PDF file in fallback and goes on with the list. google-chrome-unstable is the binary name for the unstable (also referred as "development") version of Google Chrome, while google-chrome-beta is the beta version of the browser.
The attached patch adds the browsers to the list.