Adding Chrome-side WebVR interface

content/browser/vr/vr_service.h

+// Copyright 2015 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.
+
+#ifndef CONTENT_BROWSER_VR_VR_SERVICE_H
+#define CONTENT_BROWSER_VR_VR_SERVICE_H
+
+#include <map>
+#include <set>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/memory/linked_ptr.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/threading/thread_checker.h"
+#include "content/browser/vr/vr_device.h"
+#include "content/browser/vr/vr_device_provider.h"
+#include "content/browser/vr/vr_service_consumer.h"
+#include "content/common/content_export.h"
+
+namespace blink {
+class WebVRDevice;
+}
+
+namespace content {
+
+class CONTENT_EXPORT VRService {

[mdempsky, 2015/05/11 19:25:01]

Are base::LazyInstance or Singleton not appropriate here?

[bajones, 2015/05/12 00:13:39]

This was a Singleton in a previous patchset. sievers@ suggested refactoring it
in https://codereview.chromium.org/829803003/#msg15 to prevent leaking the
singleton for the lifetime of the process.

+ public:
+  virtual ~VRService();
+
+  // Returns the VRService singleton.
+  static VRService* GetInstance();
+
+  void GetVRDevices(std::vector<blink::WebVRDevice>* webvr_devices);
+  VRDevice* GetDevice(unsigned int index);
+
+ private:
+  friend class VRServiceTest;
+  friend class VRServiceConsumer;
+
+  VRService();
+  // Constructor for testing.
+  explicit VRService(scoped_ptr<VRDeviceProvider> provider);
+
+  static void SetInstance(VRService* service);
+  static bool HasInstance();
+  static void AddConsumer(VRServiceConsumer* consumer);
+  static void RemoveConsumer(VRServiceConsumer* consumer);
+
+  void InitializeProviders();
+
+  void RegisterProvider(scoped_ptr<VRDeviceProvider> provider);
+
+  typedef std::vector<linked_ptr<VRDeviceProvider>> ProviderList;

[mdempsky, 2015/05/11 19:25:01]

FYI: I believe Chromium style is to prefer "using ProviderList =
std::vector<linked_ptr<VRDeviceProvider>>" for new code:
https://groups.google.com/a/chromium.org/d/msg/chromium-dev/8dOAMzgR4ao/G0zaw...

(Below too.)

+  ProviderList providers_;
+
+  typedef std::map<unsigned int, VRDevice*> DeviceMap;
+  DeviceMap devices_;
+
+  bool vr_initialized_;
+
+  typedef std::set<VRServiceConsumer*> ConsumerSet;
+  ConsumerSet consumers_;
+  // For testing. If true will not delete self when consumer count reaches 0.
+  bool keep_alive_;
+
+  base::ThreadChecker thread_checker_;
+
+  DISALLOW_COPY_AND_ASSIGN(VRService);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_VR_VR_SERVICE_H