Merge lp:~afrantzis/unity-system-compositor/non-blocking-swap-buffers into lp:unity-system-compositor

[Alexandros Frantzis]

Keep the compositor running even when the screen is turned off

This is needed so that the compositor can consume surface buffers and
prevent clients from blocking in eglSwapBuffers().

Keep the compositor running even when the screen is turned off

This is needed so that the compositor can consume surface buffers and
prevent clients from blocking in eglSwapBuffers().

Related Mir MPs:
https://code.launchpad.net/~afrantzis/mir/non-blocking-swap-buffers/+merge/214755
https://code.launchpad.net/~afrantzis/mir/expose-display-buffer-only-for-power-mode-on/+merge/214758

[PS Jenkins bot (ps-jenkins)]

PASSED: Continuous integration, rev:129
http://jenkins.qa.ubuntu.com/job/unity-system-compositor-ci/101/
Executed test runs:
    SUCCESS: http://jenkins.qa.ubuntu.com/job/unity-system-compositor-trusty-amd64-ci/53
    SUCCESS: http://jenkins.qa.ubuntu.com/job/unity-system-compositor-trusty-armhf-ci/53

Click here to trigger a rebuild:
http://s-jenkins.ubuntu-ci:8080/job/unity-system-compositor-ci/101/rebuild

review: Approve (continuous-integration)

[Gerry Boland (gerboland)]

This did the trick when I tested last week

review: Approve

=== modified file 'src/dbus_screen.cpp'
--- src/dbus_screen.cpp	2014-03-17 14:57:50 +0000
+++ src/dbus_screen.cpp	2014-04-08 13:41:00 +0000
@@ -40,13 +40,9 @@
         }
     );
 
-    if (mode != MirPowerMode::mir_power_mode_on)
-        compositor->stop();
-
+    compositor->stop();
     display->configure(*displayConfig.get());
-
-    if (mode == MirPowerMode::mir_power_mode_on)
-        compositor->start();
+    compositor->start();
 }
 
 // Note: this class should be created only after when the Mir DisplayServer has started