ozone: Add post message loop initialization hook

ui/ozone/public/ozone_platform.cc

 // Copyright 2014 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/command_line.h"
 #include "base/logging.h"
 #include "base/trace_event/trace_event.h"
 #include "ui/events/devices/device_data_manager.h"
 #include "ui/ozone/platform_object.h"
 #include "ui/ozone/platform_selection.h"
 #include "ui/ozone/public/ozone_platform.h"
 #include "ui/ozone/public/ozone_switches.h"
 
 namespace ui {
 
 namespace {
 
 bool g_platform_initialized_ui = false;
 bool g_platform_initialized_gpu = false;
-
+bool g_platform_initialized_gpu_post_main_loop = false;
 }
 
 OzonePlatform::OzonePlatform() {
   DCHECK(!instance_) << "There should only be a single OzonePlatform.";
   instance_ = this;
   g_platform_initialized_ui = false;
   g_platform_initialized_gpu = false;
+  g_platform_initialized_gpu_post_main_loop = false;
 }
 
 OzonePlatform::~OzonePlatform() {
   DCHECK_EQ(instance_, this);
   instance_ = NULL;
 }
 
 // static
 void OzonePlatform::InitializeForUI() {
   CreateInstance();
   if (g_platform_initialized_ui)
     return;
   g_platform_initialized_ui = true;
   instance_->InitializeUI();
   // This is deliberately created after initializing so that the platform can
   // create its own version of DDM.
   DeviceDataManager::CreateInstance();
 }
 
 // static
 void OzonePlatform::InitializeForGPU() {
   CreateInstance();
   if (g_platform_initialized_gpu)
     return;
   g_platform_initialized_gpu = true;
   instance_->InitializeGPU();
 }
 
 // static
+void OzonePlatform::InitializeForGpuPostMainLoop() {
+  DCHECK(g_platform_initialized_gpu) << "InitializeForGPU needs to be called "
+                                        "before InitializeForGpuPostMainLoop";
+  if (!base::MessageLoop::current() ||
+      g_platform_initialized_gpu_post_main_loop)
+    return;
+  g_platform_initialized_gpu_post_main_loop = true;
+
+  instance_->InitializeGpuPostMainLoop();
+}
+
+// static
 OzonePlatform* OzonePlatform::GetInstance() {
   DCHECK(instance_) << "OzonePlatform is not initialized";
   return instance_;
 }
 
 // static
 void OzonePlatform::CreateInstance() {
   if (!instance_) {
     TRACE_EVENT1("ozone",
                  "OzonePlatform::Initialize",
                  "platform",
                  GetOzonePlatformName());
     scoped_ptr<OzonePlatform> platform =
         PlatformObject<OzonePlatform>::Create();
 
     // TODO(spang): Currently need to leak this object.
     OzonePlatform* pl = platform.release();
     DCHECK_EQ(instance_, pl);
   }
 }
 
 // static
 OzonePlatform* OzonePlatform::instance_;
 
 }  // namespace ui