[oe] [meta-browser] gclient/git support

[Zoltan Kuscsik]

Hi,

I'm still in the progress of updating the meta-browse patches to a new
chromium release. It would be nice to use the  gclient to fetch the source,
but I realized that calling gclient from the recipe would break the way how
Wayland patches are added to SRC_URI.

I have submitted a gclient fetcher patch to bitbake-devel  which should
reduce
the complexity of the chromium recipes and make easier to keep Chromium in
sync with the wayland ozone project.

Here is a working example how we can fetch the full chromium source,
wayland-ozone and apply the wayland patches:

https://github.com/kuscsik/meta-testing/blob/master/recipes-core/fetcher/wayland-ozone-fetcher-test.bb

Comments are welcome.

Br,

Zoltan