ozone: Initialize a subsystem only if necessary.

ui/ozone/platform/test/ozone_platform_test.cc

 // Copyright 2013 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 "ui/ozone/platform/test/ozone_platform_test.h"
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "ui/base/cursor/ozone/cursor_factory_ozone.h"
 #include "ui/events/ozone/evdev/event_factory_evdev.h"
@@ skipping 46 matching lines @@
   gfx::FileSurfaceFactory surface_factory_ozone_;
   ui::EventFactoryEvdev event_factory_ozone_;
   ui::InputMethodContextFactoryOzone input_method_context_factory_ozone_;
   ui::CursorFactoryOzone cursor_factory_ozone_;
 
   DISALLOW_COPY_AND_ASSIGN(OzonePlatformTest);
 };
 
 }  // namespace
 
-OzonePlatform* CreateOzonePlatformTest() {
+OzonePlatform* CreateOzonePlatformTestForUI() {
   CommandLine* cmd = CommandLine::ForCurrentProcess();
   base::FilePath location = base::FilePath("/dev/null");
   if (cmd->HasSwitch(switches::kOzoneDumpFile))
     location = cmd->GetSwitchValuePath(switches::kOzoneDumpFile);
   return new OzonePlatformTest(location);
 }
 
+OzonePlatform* CreateOzonePlatformTestForGPU() {
+  return NULL;
+}
+
 }  // namespace ui