ozone: Make sure the platform doesn't get initialized more than once.

ui/ozone/ozone_platform.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 "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "ui/base/cursor/ozone/cursor_factory_ozone.h"
 #include "ui/events/ozone/event_factory_ozone.h"
 #include "ui/gfx/ozone/surface_factory_ozone.h"
 #include "ui/ozone/ime/input_method_context_factory_ozone.h"
 #include "ui/ozone/ozone_platform.h"
 #include "ui/ozone/ozone_platform_list.h"
 #include "ui/ozone/ozone_switches.h"
 
 namespace ui {
 
 namespace {
 
+bool g_platform_initialized_ui = false;
+bool g_platform_initialized_gpu = false;
+
 // Helper to construct an OzonePlatform by name using the platform list.
 OzonePlatform* CreatePlatform(const std::string& platform_name) {
   // Search for a matching platform in the list.
   for (int i = 0; i < kOzonePlatformCount; ++i)
     if (platform_name == kOzonePlatforms[i].name)
       return kOzonePlatforms[i].constructor();
 
   LOG(FATAL) << "Invalid ozone platform: " << platform_name;
   return NULL;  // not reached
 }
 
 // Returns the name of the platform to use (value of --ozone-platform flag).
 std::string GetPlatformName() {
   // The first platform is the default.
   if (!CommandLine::ForCurrentProcess()->HasSwitch(switches::kOzonePlatform) &&
       kOzonePlatformCount > 0)
     return kOzonePlatforms[0].name;
   return CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
       switches::kOzonePlatform);
 }
 
 }  // namespace
 
 OzonePlatform::OzonePlatform() {
   CHECK(!instance_) << "There should only be a single OzonePlatform.";
   instance_ = this;
+  g_platform_initialized_ui = false;
+  g_platform_initialized_gpu = false;
 }
 
 OzonePlatform::~OzonePlatform() {
   CHECK_EQ(instance_, this);
   instance_ = NULL;
 }
 
 // static
 void OzonePlatform::InitializeForUI() {
   CreateInstance();
+  if (g_platform_initialized_ui)
+    return;
+  g_platform_initialized_ui = true;
   instance_->InitializeUI();
   ui::InputMethodContextFactoryOzone::SetInstance(
       instance_->GetInputMethodContextFactoryOzone());
 }
 
 // static
 void OzonePlatform::InitializeForGPU() {
   CreateInstance();
+  if (g_platform_initialized_gpu)
+    return;
+  g_platform_initialized_gpu = true;
   instance_->InitializeGPU();
 }
 
 // static
 OzonePlatform* OzonePlatform::GetInstance() {
   CHECK(instance_) << "OzonePlatform is not initialized";
   return instance_;
 }
 
 // static
 void OzonePlatform::CreateInstance() {
   if (!instance_) {
     std::string platform = GetPlatformName();
     TRACE_EVENT1("ozone", "OzonePlatform::Initialize", "platform", platform);
     CreatePlatform(platform);
   }
 }
 
 // static
 OzonePlatform* OzonePlatform::instance_;
 
 }  // namespace ui