gl_tests: Use zero size gl surface for offscreen rendering

gpu/command_buffer/tests/gl_tests_main.cc

 // Copyright (c) 2012 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/at_exit.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/message_loop/message_loop.h"
 #if defined(OS_MACOSX)
 #include "base/mac/scoped_nsautorelease_pool.h"
 #endif
 #include "base/test/launcher/unit_test_launcher.h"
 #include "base/test/test_suite.h"
 #include "gpu/command_buffer/client/gles2_lib.h"
 #include "gpu/config/gpu_util.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "ui/gl/gl_surface.h"
+#if defined(USE_OZONE)
+#include "ui/ozone/public/ozone_platform.h"
+#endif
 
 #if defined(OS_ANDROID)
 #include "base/android/jni_android.h"
 #include "ui/gl/android/gl_jni_registrar.h"
 #endif
 
 namespace {
 
 int RunHelper(base::TestSuite* testSuite) {
+#if defined(USE_OZONE)
+  base::MessageLoopForUI main_loop;
+  ui::OzonePlatform::InitializeForUI();
+  ui::OzonePlatform::InitializeForGPU();
+  gfx::GLSurface::InitializeOneOff();
+#else
   base::MessageLoopForIO message_loop;
+#endif
   return testSuite->Run();
 }
 
 }  // namespace
 
 int main(int argc, char** argv) {
 #if defined(OS_ANDROID)
   ui::gl::android::RegisterJni(base::android::AttachCurrentThread());
 #endif
   base::TestSuite test_suite(argc, argv);
   base::CommandLine::Init(argc, argv);
 #if defined(OS_MACOSX)
   base::mac::ScopedNSAutoreleasePool pool;
 #endif
+#if !defined(USE_OZONE)
   gfx::GLSurface::InitializeOneOff();
   ::gles2::Initialize();
+#endif

[piman, 2015/03/26 20:50:13]

This concerns me slightly because ApplyGpuDriverBugWorkarounds below needs GL
(i.e. that gfx::GLSurface::InitializeOneOff ran).

Could everything move to the RunHelper?

[vignatti (out of this project), 2015/03/26 21:18:28]

I tried to be conservative and not tackle other OSs and architectures. The only
problem I found by moving this snip to the RunHelper is that InitializeOneOff
will be called several times, but things seems to work fine -- I've in fact ran
that in Linux/X11.

Do you prefer changing like that then?

[piman, 2015/03/26 21:32:49]

Why would InitializeOneOff run twice?

[vignatti (out of this project), 2015/03/27 16:00:16]

I'm not sure how the batch logic works, but the RunHelper callback will be
called every time a new batch is sent run. For example, the the default number
of tests per batch is 10 (kDefaultTestBatchLimit) and gl_tests have 94 tests, so
InitializeOneOff will be called 10 times in this case.

   gpu::ApplyGpuDriverBugWorkarounds(base::CommandLine::ForCurrentProcess());
   testing::InitGoogleMock(&argc, argv);
   return base::LaunchUnitTestsSerially(
       argc,
       argv,
       base::Bind(&RunHelper, base::Unretained(&test_suite)));
 }