ui: No more TestCompositor. Use NullDraw contexts in unit tests.

ui/aura/test/run_all_unittests.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/bind.h"
 #include "base/test/launcher/unit_test_launcher.h"
 #include "base/test/test_suite.h"
+#include "ui/gl/gl_surface.h"
 
 int main(int argc, char** argv) {
   base::TestSuite test_suite(argc, argv);
+  gfx::GLSurface::InitializeOneOffForTests();
 
   return base::LaunchUnitTests(
       argc,
       argv,
       base::Bind(&base::TestSuite::Run, base::Unretained(&test_suite)));
 }