Attempt 3 at:

chrome/test/ui/ui_test.cc

Index: chrome/test/ui/ui_test.cc
diff --git a/chrome/test/ui/ui_test.cc b/chrome/test/ui/ui_test.cc
index 7f1fe05a999602c96d37622580b55f061bae90aa..29a1b46755ea557ae0bb47139543ad4ee2c7a34e 100644
--- a/chrome/test/ui/ui_test.cc
+++ b/chrome/test/ui/ui_test.cc
@@ -56,6 +56,9 @@
 #include "base/win/windows_version.h"
 #endif
 
+#if defined(USE_AURA)
+#include "ui/gfx/compositor/compositor_switches.h"
+#endif
 
 using base::Time;
 using base::TimeDelta;
@@ -199,6 +202,12 @@ void UITestBase::SetLaunchSwitches() {
     launch_arguments_.AppendSwitchASCII(switches::kHomePage, homepage_);
   if (!test_name_.empty())
     launch_arguments_.AppendSwitchASCII(switches::kTestName, test_name_);
+#if defined(USE_AURA)
+  if (!CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kDisableTestCompositor)) {
+    launch_arguments_.AppendSwitch(switches::kTestCompositor);
+  }
+#endif
 }
 
 void UITestBase::SetUpProfile() {