glx: Turn off XSynchronize at the end of the test.

BUG=780118

Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: I58ae9e17241637331c4e0ae47fb3eeaac9761342
Reviewed-on: https://chromium-review.googlesource.com/747523Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Sadrul Chowdhury <sadrul@chromium.org>
Cr-Commit-Position: refs/heads/master@{#512979}

ui/gl/gl_context_glx_unittest.cc

@@ -47,11 +47,9 @@ TEST(GLContextGLXTest, DoNotDesrtroyOnFailedMakeCurrent) {
   ASSERT_TRUE(context->MakeCurrent(surface.get()));
   EXPECT_TRUE(context->GetHandle());
 
-  // Destroy the window, and turn off sync behaviour. We should get no x11
-  // errors so far.
+  // Destroy the window. We should get no x11 errors so far.
   context->ReleaseCurrent(surface.get());
   XDestroyWindow(xdisplay, xwindow);
-  XSynchronize(xdisplay, False);
   ASSERT_FALSE(error_tracker.FoundNewError());
 
   // Now that the window is gone, MakeCurrent() should fail. But the context
@@ -59,6 +57,7 @@ TEST(GLContextGLXTest, DoNotDesrtroyOnFailedMakeCurrent) {
   EXPECT_FALSE(context->MakeCurrent(surface.get()));
   ASSERT_TRUE(context->GetHandle());
   EXPECT_TRUE(error_tracker.FoundNewError());
+  XSynchronize(xdisplay, False);
 }
 
 }  // namespace gl