Add XDG_CURRENT_DESKTOP and GDMSESSION env to about:gpu on Linux.

Add XDG_CURRENT_DESKTOP and GDMSESSION env to about:gpu on Linux.

BUG=410560
TEST=about:gpu page on Linux
R=piman@chromium.org,kbr@chromium.org

Committed: https://crrev.com/ead6b552e80aa1f05539abff07a78e90fdac0f15
Cr-Commit-Position: refs/heads/master@{#293425}

[Zhenyao Mo, 2014-09-04 21:36:14]

Please review

[Ken Russell (switch to Gerrit), 2014-09-04 21:48:35]

LGTM with one modification.

https://codereview.chromium.org/541133002/diff/1/content/browser/gpu/gpu_inte...
File content/browser/gpu/gpu_internals_ui.cc (right):

https://codereview.chromium.org/541133002/diff/1/content/browser/gpu/gpu_inte...
content/browser/gpu/gpu_internals_ui.cc:174: {
This block should go inside the USE_X11 #if guards.

[Zhenyao Mo, 2014-09-04 21:51:54]

https://codereview.chromium.org/541133002/diff/1/content/browser/gpu/gpu_inte...
File content/browser/gpu/gpu_internals_ui.cc (right):

https://codereview.chromium.org/541133002/diff/1/content/browser/gpu/gpu_inte...
content/browser/gpu/gpu_internals_ui.cc:174: {
On 2014/09/04 21:48:34, Ken Russell wrote:
> This block should go inside the USE_X11 #if guards.

Done.

[piman, 2014-09-04 23:54:50]

LGTM.

The other thing that might be useful is to know whether or not there is a
compositing manager. This is done by checking whether the selection
"_NET_WM_CM_S0" has an owner - there's code to do that in
DesktopWindowTreeHostX11::InitX11Window

[Zhenyao Mo, 2014-09-05 00:12:10]

On 2014/09/04 23:54:50, piman (OOO) wrote:
> LGTM.
> 
> The other thing that might be useful is to know whether or not there is a
> compositing manager. This is done by checking whether the selection
> "_NET_WM_CM_S0" has an owner - there's code to do that in
> DesktopWindowTreeHostX11::InitX11Window

Thanks for the suggestion.  Will add that in a followup.

[Zhenyao Mo, 2014-09-05 00:12:21]

The CQ bit was checked by zmo@chromium.org

[commit-bot: I haz the power, 2014-09-05 00:14:21]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/zmo@chromium.org/541133002/20001

[commit-bot: I haz the power, 2014-09-05 03:47:16]

Committed patchset #2 (id:20001) as 3d53ae90183462abce4749487ee07c2c96237049

[commit-bot: I haz the power, 2014-09-10 03:36:23]

Patchset 2 (id:??) landed as
https://crrev.com/ead6b552e80aa1f05539abff07a78e90fdac0f15
Cr-Commit-Position: refs/heads/master@{#293425}