Merge lp:~vanvugt/compiz/fix-1086779 into lp:compiz/0.9.9

[Daniel van Vugt]

Remove calls to eglWaitGL which are likely to hinder performance on GLES/ARM
platforms. The calls seem to be pointless and have a significant potential
impact on performance. Also remove XFlush in the same location, apparently
pointless.
(LP: #1086779)

In case you're wondering, the calls to eglSwapBuffers and eglPostSubBufferNV ahead of the deleted code both do an implicit glFlush already.

The difference is that eglWaitGL is equivalent to a glFinish, which is completely synchronous and usually has a massive impact on performance. It will prevent the CPU and GPU from being able to operate in parallel.

[PS Jenkins bot (ps-jenkins)]

PASSED: Continuous integration, rev:3501
http://jenkins.qa.ubuntu.com/job/compiz-ci/298/
Executed test runs:
    SUCCESS: http://jenkins.qa.ubuntu.com/job/compiz-ci/./build=pbuilder,distribution=quantal,flavor=amd64/298/console

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review: Approve (continuous-integration)

[Sam Spilsbury (smspillaz)]

review: Approve

=== modified file 'plugins/opengl/src/screen.cpp'
--- plugins/opengl/src/screen.cpp	2012-11-14 10:17:09 +0000
+++ plugins/opengl/src/screen.cpp	2012-12-05 13:00:35 +0000
@@ -1882,8 +1882,6 @@
 EGLDoubleBuffer::swap () const
 {
     eglSwapBuffers (eglGetDisplay (mDpy), mSurface);
-    eglWaitGL ();
-    XFlush (mDpy);
 }
 
 bool
@@ -1908,9 +1906,6 @@
 			      r.width (),
 			      r.height ());
     }
-
-    eglWaitGL ();
-    XFlush (screen->dpy ());
 }
 
 bool