Use a mocked compositor for unit tests

ui/aura/test/test_suite.cc

Index: ui/aura/test/test_suite.cc
diff --git a/ui/aura/test/test_suite.cc b/ui/aura/test/test_suite.cc
index 5193de117af12656819e81a445f89c6387ea5388..1551de14f371e5c61b5f00bca8e064f792b05d8c 100644
--- a/ui/aura/test/test_suite.cc
+++ b/ui/aura/test/test_suite.cc
@@ -9,8 +9,9 @@
 #include "build/build_config.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_base_paths.h"
+#include "ui/gfx/compositor/test_compositor.h"
 #include "ui/gfx/gfx_paths.h"
-#include "ui/gfx/gl/gl_implementation.h"
+#include "ui/gfx/test/gfx_test_utils.h"
 
 namespace aura {
 namespace test {
@@ -19,9 +20,6 @@ AuraTestSuite::AuraTestSuite(int argc, char** argv)
     : TestSuite(argc, argv) {}
 
 void AuraTestSuite::Initialize() {
-#if defined(OS_LINUX)
-  gfx::InitializeGLBindings(gfx::kGLImplementationOSMesaGL);
-#endif
   base::TestSuite::Initialize();
 
   gfx::RegisterPathProvider();
@@ -30,6 +28,9 @@ void AuraTestSuite::Initialize() {
   // Force unittests to run using en-US so if we test against string
   // output, it'll pass regardless of the system language.
   ui::ResourceBundle::InitSharedInstance("en-US");
+
+  // Use a mock compositor that noops draws.
+  ui::gfx_test_utils::SetupTestCompositor();
 }
 
 void AuraTestSuite::Shutdown() {